Imaging apparatus and accessory

ABSTRACT

Included are multiple mount claws, and multiple contact pins following the circumferential direction of a second mount. The second mount can rotate to a first state where multiple claws of a first mount are inserted between the multiple mount claws, and a second state where the multiple mount claws engage the claws in a center axis direction. In the first state, a first mount claw is included in an angle range where a first contact pin of the multiple contact pins and a center axis of the mount are connected in the radial direction of the mount, and a first contact face of the multiple contact faces and the center axis are connected in the radial direction of the mount. The first contact pin and the first contact face come into contact first when rotating from the first state to the second state.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an imaging apparatus and an accessory.

Description of the Related Art

Conventionally, accessories such as interchangeable lenses and so forth(camera accessories) are known to be able, when mounted to an imagingapparatus such as a digital camera (hereinafter, referred to as a“camera”) or the like, to receive a supply of power from the camera andto enable communication of commands, data, and so forth between theaccessory and the camera. It is known that multiple contacts (terminals)capable of electric connection, by coming into contact, are provided onboth the camera and a mounting portion of the accessory, in order toenable the supply of power and the communication. There is also known amounting system for mounting (coupling) the accessory to the cameraemploying so-called bayonet coupling, where mounts of both the cameraand accessory are rotated relative to each other, and bayonet/mountclaws provided on each apparatus engage with the claws provided on theother apparatus.

Japanese Patent Laid-Open No. 2014-13331 proposes a technology where,with regard to an accessory and camera detachably attached by thebayonet coupling method, a predetermined contact point is disposedwithin an angle range where a bayonet claw is provided.

SUMMARY OF THE INVENTION

An imaging apparatus includes a second mount arranged to couple with afirst mount provided to an accessory. The second mount includes aplurality of mount claws that arranged to couple with a plurality ofclaws of the first mount by a bayonet coupling method, a plurality ofcontact pins that are disposed on the second mount following thecircumferential direction of the second mount, and that are arranged forelectrical connection, and a holding member configured to hold theplurality of contact pins. The second mount is arranged to be relativelyrotated as to the first mount, between a first state where the accessoryclaws are each inserted between each of the plurality of mount claws,and a second state where the plurality of mount claws are each engagedwith each of the claws of the accessory in a center axis direction ofthe second mount. Each of the plurality of contact pins correspond torespective contact faces disposed following the circumferentialdirection of the first mount at the accessory, and the correspondingplurality of contact pins and the plurality of contact faces areelectrically connected in the second state. Each of the mount clawsextend radially over an angle range in the circumferential direction ofthe second mount, and a first mount claw of the plurality of mount clawsis included in an angle range between a line where a first contact pinof the plurality of contact pins and the center axis are connected inthe radial direction of the second mount, and a line where a firstcontact face of the plurality of contact faces and the center axis areconnected in the radial direction of the second mount, in thecircumferential direction in the first state. The first contact pin is acontact pin that comes into contact first with the plurality of contactfaces, during relative rotation between the second mount and the firstmount from the first state toward the second state. The first contactface is arranged to come into contact first with the plurality ofcontact pins, during relative rotation of the second mount and the firstmount from the first state toward the second state.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings. Each of the embodiments of the present inventiondescribed below can be implemented solely or as a combination of aplurality of the embodiments. Also, features from different embodimentscan be combined where necessary or where the combination of elements orfeatures from individual embodiments in a single embodiment isbeneficial.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are block diagrams of a camera accessory and imagingapparatus according to an embodiment of the present invention.

FIGS. 2A and 2B are external perspective views of a camera body and afirst lens unit according to an embodiment of the present invention.

FIGS. 3A and 3B are disassembled perspective views of the camera bodyand the first lens unit according to an embodiment of the presentinvention.

FIGS. 4A through 4C are diagrams exemplarily describing a case ofviewing a camera mount according to an embodiment of the presentinvention from the photographer side of the camera body (rear face sideof the camera body).

FIGS. 5A and 5B are diagrams exemplarily describing engagement of thecamera body and first lens unit by camera claws at a normal position ofthe camera body according to an embodiment of the present invention.

FIGS. 6A and 6B are diagrams exemplarily describing engagement of thecamera body and first lens unit by camera claws at a vertical positionof the camera body according to an embodiment of the present invention.

FIGS. 7A and 7B are diagrams exemplarily describing a case of viewing alens mount according to an embodiment of the present invention from therear face side in a state where the first lens unit is mounted to thecamera body (side where the camera body is mounted).

FIGS. 8A and 8B are external perspective views viewing the camera mountaccording to an embodiment of the present invention from the front faceside (subject side).

FIGS. 9A and 9B are external perspective views of the lens mountaccording to an embodiment of the present invention, as viewed from theside to which the camera mount is mounted (rear face side).

FIGS. 10A and 10B are diagrams exemplarily describing a contact statebetween terminals on the camera body and first lens unit according to anembodiment of the present invention.

FIGS. 11A and 11B are diagrams describing a first conversion adapterthat is mountable to the camera body, and a second lens unit.

FIGS. 12A and 12B are diagrams describing a second conversion adapterthat is mountable to a camera body, and the first lens unit.

FIGS. 13A through 13C is a diagram for exemplarily describing angle sodisposing bayonet claws in a camera mount provided on one end of thefirst conversion adapter.

FIGS. 14A and 14B are diagrams exemplarily describing angle so disposingbayonet claws in the lens mount provided on the other end of the firstconversion adapter.

FIGS. 15A and 15B are diagrams exemplarily describing a mounting methodof a predetermined imaging apparatus and a predetermined lens unithaving claws and recesses that interfere with each other.

FIGS. 16A and 16B are diagrams exemplarily describing the way in whichclaws interfere with each other when attempting to mount the lens mountside to the camera mount side according to an embodiment of the presentinvention.

FIGS. 17A through 17D is a diagram exemplarily describing a case ofattempting to insert incompatible claws into recesses at the lens mountside and camera mount side according to an embodiment of the presentinvention.

FIGS. 18A and 18B are diagrams exemplarily describing angle so disposingbayonet claws in the camera mount provided on one end of the secondconversion adapter.

FIGS. 19A through 19C are diagrams exemplarily describing angle sodisposing bayonet claws in a lens mount provided on the other end of thesecond conversion adapter.

FIGS. 20A and 20B are diagrams exemplarily describing the way in whichclaws interfere with each other, when attempting to mount a referenceclaw at the lens mount side to a reference recess at the camera mountside according to an embodiment of the present invention.

FIGS. 21A through 21D are diagrams exemplarily describing the way inwhich claws interfere with each other, when attempting to mount a clawother than the reference claw at the lens mount side to a referencerecess at the camera mount side according to an embodiment of thepresent invention.

FIG. 22 is a diagram exemplarily describing a state in which clawsprovided to the camera mount side and lens mount side according to anembodiment of the present invention are engaged.

FIG. 23 is a diagram exemplarily describing contact timing for engagingof claws with each other and contact among contact points whendetachably attaching the lens mount to the camera mount in an embodimentof the present invention.

FIG. 24 is a disassembled perspective view of a mount mechanismaccording to a modification of the present invention.

FIGS. 25A through 25C are diagrams for exemplarily describing anon-coupled state of the mount mechanism according to the modificationof the present invention.

FIGS. 26A through 26C are diagrams for exemplarily describing a coupledstate of the mount mechanism according to the modification of thepresent invention.

DESCRIPTION OF THE EMBODIMENTS

FIGS. 1A and 1B are block diagrams of a camera accessory and imagingapparatus according to an embodiment of the present invention. FIG. 1Ais a diagram exemplarily describing a camera system including a firstlens unit (hereinafter referred to as first lens) 100, serving as anaccessory according to the embodiment of the present invention, and acamera body 10 serving as a first imaging apparatus to which the firstlens 100 can be directly detachably attached. Also, FIG. 1B is a diagramdescribing the configuration of a mount portion 1 formed by the mountsin both the first lens 100 and the camera body 10. That is in FIGS. 1Aand 1B, the mounts provided on the first lens 100 and the mountsprovided on the camera body 10 are collectively referred to as the mountportion 1. The mounts provided to the first lens 100 and camera body 10will be described later.

As illustrated in FIG. 1A, the camera body 10 has a charge-accumulationtype solid-state imaging device (hereinafter referred to simply assensor) 11, such as a complementary metal-oxide semiconductor (CMOS)sensor or the like, that performs photoelectric conversion of an opticalimage of a subject guided by a photography lens group 101 provided onthe inner side of the first lens 100, and outputs electric signals. Thecamera body 10 also has an A/D conversion unit 12 that converts analogelectric signals output from the imaging sensor 11, and an imageprocessing unit 13 that generates image signals by performing varioustypes of image processing on the digital signals. The image signals(still image and moving image) generated at the image processing unit 13can be displayed on a display unit 14, and recorded in a recordingmedium 15.

The camera body 10 also has memory 16. This memory 16 serves as a bufferfor performing processing on image signals, and also stores operationprograms (computer programs) that a later-described camera control unit18 uses.

The camera body 10 also has a camera operating input unit 17 including apower source switch for turning the power source on/off, a photographyswitch (release switch) for starting recording of image signals, andselection/settings switches for performing various types of menusettings, and so forth. The camera body 10 also has the camera controlunit 18 including a microprocessor central processing unit (CPU) servingas a computer) that centrally controls the operations of the camera body10 and first lens 100. The camera control unit 18 performs various typesof settings based on signals input from the camera operating input unit17, for example, and controls communication with a lens control unit 103provided to the first lens 100 via the mount portion 1.

On the other hand, the first lens 100 has the photography lens group 101that is an optical member having multiple lens groups such as a zoomlens, shift lens, focus lens, and so forth, and light amount adjustmentmembers such as a diaphragm and so forth. The first lens 100 hasactuators for moving or operating optical members such as the multiplelens groups and diaphragm and so forth, and also has a lens drive unit102 that drives the actuators. The first lens 100 also has the lenscontrol unit 103 including a microprocessor (logical CPU (LCPU)) forlenses, that centrally controls operations of the first lens 100. Thelens control unit 103 controls the lens drive unit 102 by communicatingwith the camera control unit 18 via the mount portion 1, for example.

Basic Configuration of Mount Portion 1

Next, the configuration of the mount portion 1 including a camera mountface A provided on the camera body 10 side, and an accessory mount faceB provided on the first lens 100 side, will be described with referenceto FIG. 1B. Note that the camera mount and accessory mount include alocking mechanism, a mount holding mechanism, and multiple electricterminals. The mounts will be described in detail later.

The mount portion 1 has multiple terminals that are capable ofelectrically connecting the camera body 10 and the first lens 100 toeach other, as illustrated in FIG. 1B. The multiple terminals are, atthe camera mount face A, exposed to the outside of the camera body 10 asmultiple camera-side contact pins provided to a contact holding member203. The multiple terminals also are, at the accessory mount face B,exposed to the outside of the camera accessory (e.g., first lens 100) asmultiple accessory-side contact faces provided to a contact face holdingmember 303. The contact pins and the contact faces of the camera body 10side and the camera accessory (e.g., first lens 100) side areelectrically connected among mutually corresponding contacts, in a statewhere the camera accessory is mounted to the camera body 10.

A camera power source unit 19 generates communication control powersource (VDD) as power source to be supplied to a mounted cameraaccessory via a VDD terminal, and power source to be supplied to a firstcommunication I/F unit 21 a via a power source switching unit 20. Thecamera power source unit 19 also generates driving power source (VBAT)as power source to be supplied to the mounted camera accessory via aVBAT terminal.

The camera power source unit 19 generates a 3.3 V power source as apower source to be supplied to the camera control unit 18, firstcommunication I/F unit 21 a, and a second/third communication I/F unit21 b. The camera power source unit 19 also generates 3.0 V power sourceas a power source to be supplied to the first communication I/F unit 21a and second/third communication I/F unit 21 b via the power sourceswitching unit 20.

The power source switching unit 20 is connected to the camera powersource unit 19. The power source switching unit 20 supplies only one orthe other of the VDD and 3.0 V power source, generated at the camerapower source unit 19, to the first communication I/F unit 21 a as powersource Vs for communication interface. Switching of power source voltageis executed following instructions from the camera control unit 18.

Next, a lens power source 104 generates a 3.0 V power source, as a powersource voltage for supply to the lens control unit 103 and a lens-sideI/F unit 106, based on VDD supplied from the camera body 10 side. In astate where the first lens 100 is mounted to the camera body 10, drivingpower source (VBAT) is supplied to a drive circuit unit 105 at the firstlens 100 side, via a VBAT terminal from the above-described camera powersource unit 19.

Although the power source voltage for the lens control unit 103 andlens-side I/F unit 106 is the same (3.0 V) in the present embodiment, aconfiguration may be made where the voltage level that the lens controlunit 103 exhibits is 3.3 V. In this case, there is the need to supplypower source of a voltage level of 3.0 V and 3.3 V to the lens-side I/Funit 106, so the lens power source 104 generates power sources of 3.0 Vand 3.3 V.

Hereafter, the functions of the terminals common to both the cameramount face A and accessory mount face B will be described. VDD terminals203 a and 303 a are terminals that supply communication control powersource (VDD) as communication power primarily used for communicationcontrol, to the camera accessory (e.g., the first lens 100) from thecamera body 10. Note that while the voltage of power source supplied tothe first lens 100 is 5.0 V, the voltage of supplied power source willchange depending on the type of accessory mounted to the camera body 10.

VBAT terminals 203 b and 303 b are terminals that supply driving voltagesource (VBAT) that is driving power used for operating the mechanicaldriving units of the actuators used for driving the diaphragm and focuslens, from the camera side to the camera accessory side. In other words,the VBAT terminals 203 b and 303 b are terminals used to supply powersource other than the above-described communication power. Note that thevoltage of the power source serving as driving power supplied to thefirst lens 100 is 4.25 V. The VDD terminals 203 a and 303 a and VBATterminals 203 b and 303 b described above are power source terminals forsupplying power source from the camera body 10 to the camera accessory,for example.

DGND terminals 203 m and 303 m are grounding terminals GND terminals)corresponding to the communication control power source VDD. Note thatgrounding in the present embodiment means to set the voltage level ofthe grounding terminals to generally the same level as the negative poleside of the power source such as a battery or the like.

PGND terminals 203 d and 303 d are grounding terminals for connectingthe camera body 10, and a mechanical drive system including motors(actuators) and the like provided to a camera accessory (e.g., the firstlens 100), to ground level. That is to say, the PGND terminals 203 d and303 d are grounding terminals (GND terminals) corresponding to thedriving power source VBAT. The DGND terminals 203 m and 303 m and PGNDterminals 203 d and 303 d described above are grounding terminals forgrounding various types of power source systems in the camera body 10and accessory to the ground level.

MIF terminals 203 e and 303 e are terminals for detecting that thecamera accessory (e.g., the first lens 100) has been mounted to thecamera body 10. In the present embodiment, the MIF terminals 203 e and303 e detect that the first lens 100 has been mounted to the camera body10.

The camera control unit 18 detects that the camera accessory has beenmounted to or detached from the camera body 10, by detecting the voltagelevel that the MIF terminals 203 e and 303 e indicated. Based on thisdetection, the camera control unit 18 starts supply of power source topower source terminals after having detected mounting of the cameraaccessory, for example, and effects control to start communicationbetween the camera body 10 and camera accessory.

TYPE terminals 203 c and 303 c are terminals for distinguishing the typeof camera accessory (e.g., the first lens 100) mounted to the camerabody 10. The camera control unit 18 detects the value of voltage ofsignals indicated by the TYPE terminals 203 c and 303 c, anddistinguishes the type of camera accessory mounted to the camera body 10based on this value. Note that the first lens 100 is pull-down connectedto the DGND terminal at a predetermined resistance value. Thisresistance value differs depending on the type of the camera accessory.

Next, description will be made regarding various types of communicationterminals between the camera body 10 and the camera accessory. Note thatthe multiple communication terminals provided to the mount portion 1 aredivided into multiple communication systems (groups), and eachcommunication system is capable of performing communicationindependently. In the present embodiment, LCLK terminals 203 h and 303h, DCL terminals 203 f and 303 f, and DLC terminals 203 g and 303 g, area first communication system that performs first communication. DLC2terminals 203 i and 303 i are a second communication system thatperforms second communication, which is independent from the firstcommunication. Further, CS terminals 203 k and 303 k, and DCA terminals203 j and 303 j are a third communication system that performs thirdcommunication, which is independent from the first and secondcommunication. In the present embodiment, the camera control unit 18 andlens control unit 103 can perform communication independently with thefirst through third, via the above-described multiple communicationterminals.

LCLK terminals 203 h and 303 h are terminals of the first communicationsystem, and are terminals for communication clock signals output fromthe camera body 10 to the camera accessory (e.g., the first lens 100),and terminals for the camera body 10 to monitor the busy state of theaccessory. DCL terminals 203 f and 303 f are terminals of the firstcommunication system, and are communication data terminals forperforming bidirectional communication between the camera body 10 andthe camera accessory (e.g., the first lens 100). DLC terminals 203 g and303 g are terminals of the first communication system, and are terminalsfor communication data output from the camera accessory (e.g., the firstlens 100) to the camera body 10.

The above-described LCLK terminals, DCL terminals, and DLC terminals,corresponding to the first communication system, can switch the signaloutput format between so-called CMOS output type and open type. In thepresent embodiment, the CMOS output type has switch output of voltage atboth H (High) and L (Low). In comparison with this, the open type hasswitch output at only the L side. Although open type in the presentembodiment means the so-called open drain type, this may be the opencollector type.

DLC2 terminals 203 i and 303 i are terminals of the second communicationsystem, and are terminals for communication data output from the cameraaccessory (e.g., the first lens 100) to the camera body 10. DCAterminals 203 j and 303 j are terminals of the third communicationsystem, and are terminals for communication data for performingbidirectional communication between the camera body 10 and the cameraaccessory (e.g., the first lens 100). CS terminals 203 k and 303 k areterminals of the third communication system, and are signals terminalsfor communication requests between the camera body 10 and cameraaccessory (e.g., the first lens 100). Note that in the presentembodiment, in a case where the first lens 100 is mounted to the camerabody 10, the communication voltage at the corresponding terminals in thefirst through third communication systems is 3.0 V.

Configuration of Camera Mount and Accessory Mount

The configuration of the camera mount 201 and the lens mount (accessorymount) 301 according to the present embodiment will be described withreference to FIGS. 2A through 3B. Note that in the followingdescription, the mount provided to the imaging apparatus side will bereferred to as camera mount, and the mount provided to the lens unitside will be referred to as lens mount. Further, of mounts on alater-described conversion adapter, the side that is mounted to theimaging apparatus will be referred to as lens mount, and the sidemounted to the lens unit will be referred to as camera mount. Note thatin the following description, a second conversion adapter 70 has acamera mount 1201 that is the same as the camera mount 201 of the camerabody 10. And note that in the following description, a first conversionadapter 40 has a lens mount 1301 that is the same as the lens mount 301of the first lens 100.

FIGS. 2A and 2B are external perspective views of the camera body 10 andfirst lens 100 according to the embodiment of the present invention.FIG. 2A illustrates a state in which the first lens 100 is mounted tothe camera body 10, and FIG. 2B illustrates a state in which the firstlens 100 has been removed from the camera body 10.

As illustrated in FIGS. 2A and 2B, the camera body 10 and first lens 100have a ring-shaped camera mount 201 and ring-shaped lens mount 301,which each have contact faces which are parallel in a directionorthogonal to the optical axis and as such are arranged to cooperatewith each other in use. Although the camera mount 201 and the lens mount301 are ring shaped, this is not restrictive in the present embodiment.For example, a configuration may be employed in the configuration wherethis is realized by each of the camera mount 201 and lens mount 301having arc-shaped contact faces. In other words, a configuration may beemployed where this is realized by the camera mount 201 and the lensmount 301 having a part of the contact face notched out. Note that theabove-described optical axis is parallel to a center axis passingthrough the center of an aperture of the camera mount and lens mount. Inthe present embodiment, the center axis of the camera mount 201 and thecenter axis of the lens mount 301 are same as each optical axis of thecamera mount 201 or lens mount 301. In the present embodiment, aconfiguration may be employed where this is realized by differing thecenter axis of the mount from the optical axis. By rotating the camerabody 10 and first lens 100 relative to each other, in a state where thereference faces of each of the camera mount 201 and lens mount 301 arein contact with each other, from an unlocked position to a lockedposition, the first lens 100 is mounted to the camera body 10. This willbe described in detail later.

FIGS. 3A and 3B are disassembled perspective views of the camera body 10and first lens 100 according to the embodiment of the present invention.FIG. 3A illustrates a disassembled perspective view of the camera body10, and FIG. 3B illustrates a disassembled perspective view of the firstlens 100.

As illustrated in FIG. 3A, a first optical axis (first center axis) 3000indicates a light flux passing through the center of the camera mount201 of the camera body 10 as illustrated in FIG. 3A. Also, asillustrated in FIG. 3B, an optical axis 3001 is an axis for describing alight flux representing an optical image of a subject that is guided bythe first lens 100. When the first lens 100 is mounted to the camerabody 10, the first optical axis 3000 and optical axis 3001 describedabove match, and optical fluxes corresponding to these optical axesenter the imaging sensor 11 and are imaged, thereby imaging a subjectimage.

A lock pin 202 is first restricting member (lock member) for restricting(locking) the mounted state of the camera body 10 and camera accessory.Note that the lock pin 202 is capable of advancing and retreating in adirection parallel to the first optical axis 3000. Specifically, whenthe first lens 100 is mounted to the camera body 10, the lock pin 202enters a lock groove 301 z that is a second restricting member providedto the lens mount 301, and locks the state of the first lens 100 beingmounted to the camera body 10. The locking of the first lens 100 mountedto the camera body 10 can be disengaged by the user operating a lockdisengaging member (omitted from illustration) connected to the lock pin202, thereby retracting the lock pin 202 from the lock groove 301 z.Note that even in a case of further rotating the first lens 100 andcamera body 10 relative to each other in the mounting direction with thelock disengaging member operated, rotation beyond a lock abutting face301 y is restricted (see FIG. 7A).

The contact holding member 203 is a holding unit for holdinglater-described (see FIGS. 8A and 8B) multiple contact pins (electricalcontact unit) 203 a through 203 k and 203 m, provided on the camera body10 side. Note that in the present embodiment, the contact pins andcontact faces corresponding to the above-described terminals are denotedby the same part numerals as the terminals for the sake of description.

A camera body member 204 is a camera housing that holds the members ofthe camera body 10. Specifically, the above-described camera mount 201and contact holding member 203 are fastened to the camera body member204 by camera mount fastening screws 205 a through 205 d and contactholding member fastening screws that are omitted from illustration.Camera mount fastening screws 205 a through 205 d are positioned wherenone of multiple leaf springs 206 a, 206 b, and 206 c are positioned inthe camera mount 201. Furthermore, camera mount fastening screws 205 athrough 205 d are exposed at the contact faces of the camera mount 201which is contact with the contact face of the lens mount 301. Althoughthe camera body member 204 holds an unshown imaging unit to which theaforementioned imaging sensor 11 is mounted, and a shutter unit that isomitted from illustration, description will be omitted.

The lens mount biasing member 206 is a biasing unit at the imagingapparatus side to pull lens claws 301 d and 301 e, which are multiplebayonet claws provided to the later-described lens mount 301, toward thecamera mount 201 side. Specifically, the lens mount biasing member 206has multiple leaf springs 206 a, 206 b, and 206 c, and the bayonet clawsprovided to the first lens 100 are biased in the optical axis directionby the leaf springs. Note that the lens mount biasing member 206 is heldbetween the camera mount 201 and camera body member 204 in a spaceformed therebetween.

Next, a front lens 101 a and rear lens 101 b are optical members makingup the photography lens group 101, as illustrated in FIG. 3B. While thephotography lens group 101 has multiple lenses, only the front lens 101a disposed at the subject-side end and the rear lens 101 b disposed atthe camera body 10 side end are illustrated in the present embodiment tosimplify description.

A lens barrel 302 is a holding member that holds the photography lensgroup 101. Note that the lens mount 301 is fastened to the lens barrel302 by lens mount fastening screws 304 a through 304 d. A contact faceholding member 303 is a holding unit for holding multiple contact faces(electrical contact unit) 303 a through 303 k and 303 m provided to alater-described (see FIGS. 9A and 9B) first lens 100 side. The contactface holding member 303 is fastened to the lens mount 301 by lenscontact holding portion fastening screws 305 a and 305 b. The lens mountfastening screws 304 a through 304 d are exposed at the contact faces ofthe lens mount 301 which is in contact with the contact face of thecamera mount 201.

Configuration of Bayonet Claws at Camera Body 10 Side

Next, the multiple bayonet claws provided to the camera mount 201 at thecamera body 10 side will be described with reference to FIGS. 4A through6B. FIGS. 4A through 4C are diagrams exemplarily describing a case ofviewing the camera mount 201 according to the embodiment of the presentinvention from the photographer side (rear face side of the camera body10) of the camera body 10. FIG. 4A is a diagram illustrating angleranges that camera mount claws (hereinafter referred to simply as cameraclaws) and camera mount recesses (hereinafter referred to simply ascamera recesses) having the lock pin 202 as a reference occupy in thecircumferential direction of the camera mount 201. The camera recessesof the camera mount 201 are notch portions between adjacent cameraclaws. Camera recesses of the camera mount 201 are formed further towardthe outside in the radial direction from the center axis of the cameramount 201 than the camera claws of the camera mount 201. Also, lensrecesses of the lens mount 301 are formed further toward the inside inthe radial direction from the center axis of the lens mount 301 than thelens claws of the lens mount 301. FIG. 4B is a diagram illustratingangle ranges that multiple camera claws 201 a through 201 c occupy inthe circumferential direction of the camera mount 201. FIG. 4C is across-sectional diagram taken along cross-section IVC-IVC in FIG. 4B.

Note that in the following description, protrusions protruding fromrecesses in the inner radial direction at the camera mount side will bereferred to as camera claws, and protrusions protruding from recesses inthe outer diameter direction at the later-described lens mount(accessory mount) side will be referred to as lens mount claws. In thefollowing description, the side of the camera mount 201 as viewed fromthe side of the photographer (rear face of the camera body 10) of thecamera body 10 will be referred to as rear face side, and the oppositeside will be referred to as front face side (or camera accessory side).It should be noted that in the following description, description willbe made with a case of viewing the camera mount 201 from the rear faceside as a reference, but in a case of viewing the camera mount 201 fromthe front face side, angles and directions stipulating angles(clockwise, etc.) will be reversed.

A first camera claw 201 a, second camera claw 201 b, and third cameraclaw 201 c, are provided in order, to the camera mount 201 in thecircumferential direction (inner radial direction), as illustrated inFIGS. 4A and 4B. When viewing the camera mount 201 from the rear faceside as illustrated in FIGS. 4A and 4B, the camera claw that is providedat a position farthest from the lock pin 202 is the first camera claw201 a. The second camera claw 201 b and third camera claw 201 c are thenconsecutively provided in order from the first camera claw 201 a in aclockwise direction.

Also, recesses which are a first camera recess 201 d, second camerarecess 201 e, and third camera recess 201 f are provided in order, tothe camera mount 201 in the circumferential direction (inner radialdirection). When viewing the camera mount 201 from the rear face side asillustrated in FIGS. 4A and 4B, the recess that is provided at aposition nearest to the lock pin 202 is the second camera recess 201 e.The third camera recess 201 f and first camera recess 201 d are thenconsecutively provided in order from the second camera recess 201 e in aclockwise direction.

As illustrated in FIG. 4C, a fitting member 201 x that restrictsmovement of the camera accessory in a direction parallel to the opticalaxis when the camera accessory is mounted, is provided to the cameramount 201 side in the circumferential direction. In the presentembodiment, the diameter of the fitting member 201 x in a directionorthogonal to the optical axis at the camera mount 201 is the mountdiameter.

To mount the first lens 100 to the camera body 10, first, the cameraclaws of the camera body 10 are inserted into the lens mount recesses ofthe first lens 100, and the lens mount claws at the first lens 100 sideare inserted into the camera recesses at the camera body 10 side. Thisstate is a mounting start state (first state). Note that in thefollowing description, accessory mount recesses will be referred tosimply as accessory recesses, and accessory mount claws will bereference to simply as accessory claws. For example, in the case of thelens mount 301, this is lens recesses and lens claws.

The camera mount 201 and lens mount 301 are then rotated relative toeach other from the mounting start state, whereby the camera claws andlens claws engage in the radial direction orthogonal to the opticalaxis, and transition to a state where the lens claws are biased by theabove-described lens mount biasing member 206. In this state, relativepositional relation between the camera body 10 and the first lens 100transitions to a locked state where the lock pin 202 has fit into thelock groove 301 z as described above. This state is a mounting completestate (second state). Note that in the mounting complete state, contactof corresponding terminals at the camera mount 201 and lens mount 301 iscomplete.

As described above, the camera claws and accessory claws are so-calledbayonet claws, and as described above, have shapes so that the firstlens 100 can be mounted (can be coupled) to the camera body 10 by theso-called bayonet coupling method by engaging of the camera claws andaccessory claws.

Note that the end portions of the camera claws 201 a, 201 b, and 201 c,in the circumferential direction, will be referred to as first endportion 201 a 1, second end portion 201 a 2, third end portion 201 b 1,fourth end portion 201 b 2, fifth end portion 201 c 1, and sixth endportion 201 c 2, for the same of description. The end portions aredenoted with part numerals in order from the first camera claw 201 a inthe clockwise direction, when viewing the camera mount 201 from the rearface side, as described above.

As illustrated in FIG. 4A, the angles that the camera claws and camerarecesses occupy in the circumferential direction of the camera mount 201(angle ranges) are stipulated as follows in the present embodiment. Forthe first camera claw 201 a, the angle θa=48°, for the second cameraclaw 201 b, the angle θb=40°, and for the third camera claw 201 c, theangle θc=92°. Also, for the first camera recess 201 d, the angle is 57°,for the second camera recess 201 e, the angle is 66°, and for the thirdcamera recess 201 f, the angle is 57°.

Also, when viewing the camera claws from the rear face side of thecamera body 10, the angles in the clockwise direction where the cameraclaws are disposed in the circumferential direction of the camera mount201 with the position of the lock pin 202 (referred to as referenceposition) as a reference are stipulated as follows. The first cameraclaw 201 a is disposed between 169° to 217° with the reference positionas a start point. The second camera claw 201 b is disposed between 274°to 314° with the reference position as a start point. The third cameraclaw 201 c is disposed between 20° to 112° with the reference positionas a start point.

Now, when viewing the camera mount 201 from the optical axis directionin the present embodiment, of the multiple bayonet claws, the thirdcamera claw 201 c overlaps a first camera mount center line 3003 thatextends in the vertical direction from the center axis parallel with theoptical axis of the camera mount 201 in the radial direction of thecamera mount 201. Note that the first camera mount center line 3003 is aline that, in a normal position of the camera body 10 where the lock pin202 is situated at the left side when viewing the camera mount 201 fromthe front face side, extends in the gravitational direction and theopposite direction from the gravitational direction, from the center(optical axis) of the camera mount 201. That is to say, the first cameramount center line 3003 is a vertical line that passes through theoptical axis in a normal position of the camera. In other words, thefirst camera mount center line 3003 is a vertical line that passesthough the center of the camera mount 201 and orthogonal to the centeraxis of the camera mount 201 when the camera body 10 is placed on ahorizontal plane.

As opposed to this, a line that, in a vertical position of the camerabody 10 where the lock pin 202 is situated at the top side when viewingthe camera mount 201 from the front face side, extends in thegravitational direction and the opposite direction from thegravitational direction, from the center (optical axis) of the cameramount 201, is a second camera mount center line 3002. That is to say,the second camera mount center line 3002 is a horizontal line thatpasses through the optical axis when the camera body 10 is in the normalposition. The second camera mount center line 3002 overlaps the lock pin202 and first camera claw 201 a in the radial direction of the lensmount 201. Note that the first camera mount center line 3003 and thesecond camera mount center line 3002 are generally orthogonal.

FIGS. 5A and 5B are diagrams exemplarily describing engagement of thecamera body 10 and first lens 100 by camera claws at a normal positionof the camera body 10 according to the embodiment of the presentinvention. FIG. 5A is a diagram viewing a state where the first lens 100is mounted to the camera body 10 from the front face side. FIG. 5B is apartial cross-sectional view of the camera body 10 and first lens 100taken along cross-section VB-VB in FIG. 5A. Note that in FIGS. 5A and5B, the camera body 10 is positioned in the above-described normalposition, and, in this state, a camera grip 204 a provided to the camerabody member 204 is situated to the left side when viewing the camerabody 10 from the front face side.

FIGS. 6A and 6B are diagrams exemplarily describing engagement of thecamera body 10 and first lens 100 by bayonet claws at a verticalposition of the camera body 10 according to the embodiment of thepresent invention. FIG. 6A is a diagram viewing a state where the firstlens 100 is mounted to the camera body 10 from the front face side. FIG.6B is a partial cross-sectional view of the camera body 10 and firstlens 100 taken along cross-section VIB-VIB in FIG. 6A. Note that inFIGS. 6A and 6B, the camera body 10 is positioned in the above-describedvertical position, and the camera grip 204 a in this state is situatedto the top side when viewing the camera body 10 from the front faceside.

Generally, in a case of mounting an interchangeable lens to a camera, agap occurs between the camera and interchangeable lens in a directionorthogonal to the optical axis, due to dimensional tolerance of the two,and looseness of the lens as to the camera increases due to this gap.Particularly, in a case of coupling a camera and interchangeable lens bybayonet coupling, the looseness of the lens is greater the farther awayfrom positions where the bayonet claws engage each other in thecircumferential direction of the lens. Also, the looseness in thegravitational direction (bowing) of the interchangeable lens as to thecamera is greater due to the weight of the interchangeable lens itself.Accordingly, if a subject is imaged in a case where the looseness of theinterchangeable lens as to the camera is great, an unnatural image maybe obtained that is unintended by the user, due to the deviation ofoptical axis of the camera and optical axis of the lens.

Accordingly, in the present embodiment, the third camera claw 201 c thathas the widest angle of the camera-side bayonet claws overlaps the firstcamera mount center line 3003 in the radial direction of the cameramount, as illustrated in FIG. 5B. According to this configuration, whenthe first lens 100 is mounted to the camera body 10, the first cameramount center line 3003 overlaps the position where the third camera claw201 c and a later-described third lens claw 301 f are engaged. In thiscase, looseness (bowing) of the camera accessory such as the first lens100 or the like mounted to the camera body 10 in the gravitationaldirection, can be suppressed in the normal position of which thefrequency of usage is highest for operating the imaging apparatus, forexample. Due to the above-described configuration, the gap Δ1illustrated in FIG. 5B can be kept from becoming large, so looseness ofthe first lens 100 as to the camera body 10 in the direction indicatedby the arrow in FIG. 5B can be suppressed.

Also, in the present embodiment, the first camera claw 201 a overlapsthe second camera mount center line 3002, as illustrated in FIG. 6B inthe radial direction of the camera mount 201. According to thisconfiguration, when the first lens 100 is mounted to the camera body 10,the second camera mount center line 3002 overlaps the position where thefirst camera claw 201 a and a later-described first lens claw 301 d areengaged. In this case, looseness (bowing) of the camera accessory suchas the first lens 100 or the like mounted to the camera body 10 in thegravitational direction, can be suppressed in the vertical position ofthe imaging apparatus as well, for example. Due to the above-describedconfiguration, the gap Δ2 illustrated in FIG. 6B can be kept frombecoming large, so looseness of the first lens 100 as to the camera body10 in the direction indicated by the arrow in FIG. 6B can be suppressed.

Also, the angle of the third camera claw 201 c in the circumferentialdirection of the camera mount 201, situated at the top side in a casewhere the camera body 10 is at the normal position, is greater than thesum of angles of the first claw 201 a and second claw 201 b situated atthe lower side, as illustrated in FIG. 4B. More precisely, the total sumof angles in the circumferential direction of the camera claws providedto the camera mount 201 is greater at the upper side of the secondcamera mount center line as a reference as compared to the lower side.Specifically, the sum of angle θc and the angle θa1 of the first cameraclaw 201 a on the upper side of the second camera mount center line 3002is larger than the sum of angle θb and the angle θa2 of the first cameraclaw 201 a on the lower side of the second camera mount center line3002. That is to say, the layout of the camera claws and recesses isdecided so as to satisfy the two following expressions.

θc≥θa+θb  (1)

θa1+θc>θa2+8b  (2)

According to this configuration, in the normal position of the camerabody 10 regarding which the frequency of usage is highest, the strengthof camera claws at the upper side of the second camera mount center line3002 (opposite side from the gravitational direction) that indicates thehorizontal direction of the camera mount 201 can be made to be greaterthan the camera claws at the lower side (gravitational direction).Accordingly, in the normal position of the camera body 10 regardingwhich the frequency of usage is highest in a state where the first lens100 is mounted, the camera body 10 according to the present embodimentcan reduce looseness (bowing) of the first lens 100 as to the camerabody 10 in the gravitational direction. Also, according to the camerabody 10 of the present embodiment, in the normal position of the camerabody 10 regarding which the frequency of usage is highest in a statewhere the first lens 100 is mounted, deformation of camera claws andlens claws due to the weight of the first lens 100 itself can besuppressed.

Configuration of Bayonet Claws at First Lens 100 Side

Next, multiple lens claws (accessory claws) provided to the lens mount301 at the first lens 100 side will be described with reference to FIGS.7A and 7B. FIGS. 7A and 7B are diagrams exemplarily describing a case ofviewing the lens mount 301 according to the embodiment of the presentinvention from the rear face side in a state where the first lens 100 ismounted to the camera body 10 (side where the camera body 10 isattached). FIG. 7A exemplarily describes angles of the claws andrecesses in the circumferential direction at the lens mount 301 side,and FIG. 7B is a cross-sectional view taken along cross-sectionVIIB-VIIB in FIG. 7A. Note that in the following description, the camerabody 10 is positioned in the normal position in the state illustrated inFIGS. 7A and 7B.

A first lens claw 301 d, second lens claw 301 e, and third lens claw 301f, are provided in order, to the lens mount 301 in the circumferentialdirection (inner radial direction), as illustrated in FIG. 7A. Whenviewing the lens mount 301 from the rear face side as illustrated inFIG. 7A, the lens claw that is provided at a position farthest from thelock groove 301 z is the first lens claw 301 d. The second lens claw 301e and third lens claw 301 f are then consecutively provided in orderfrom the first lens claw 301 d in a clockwise direction.

Also, recesses which are a first lens recess 301 a, second lens recess301 b, and third lens recess 301 c are provided in order, to the lensmount 301 in the circumferential direction (inner radial direction).When viewing the lens mount 301 from the rear face side as illustratedin FIG. 7A, the recess that is provided at a position nearest to thelock groove 301 z is the third lens recess 301 c. The first lens recess301 a and second lens recess 301 b are then consecutively provided inorder from the third lens recess 301 c in a clockwise direction.

As illustrated in FIG. 7B, a fitting member 301 x that restrictsmovement in a direction parallel to the optical axis of the imagingapparatus when mounted on the imaging apparatus, is provided to the lensmount 301 side in the circumferential direction. In the presentembodiment, the diameter of the fitting member 301 x in a directionorthogonal to the optical axis at the lens mount 301 side is the mountdiameter.

Note that the end portions of the lens claws 301 d, 301 e, and 301 f, inthe circumferential direction, will be referred to as first end portion301 d 1, second end portion 301 d 2, third end portion 301 e 1, fourthend portion 301 e 2, fifth end portion 301 f 1, and sixth end portion301 f 2. The end portions are denoted with part numerals in order fromthe first lens claw 301 d in the clockwise direction, when viewing thelens mount 301 from the rear face side, as described above.

As illustrated in FIG. 7A, the angles that the lens claws and lensrecesses occupy in the circumferential direction of the lens mount 301(angle ranges) are stipulated as follows in the present embodiment. Forthe first lens claw 301 d, the angle θd=53°, for the second lens claw301 e, the angle θe=62°, and for the third lens claw 301 f, the angleθf=53°. Also, for the first lens recess 301 a, the angle is 52°, for thesecond lens recess 301 b, the angle is 44°, and for the third lensrecess 301 c, the angle is 96°.

Also, when viewing the lens claws from the rear face side, the angleswhere the lens claws are disposed in the circumferential direction ofthe lens mount 301 with the position of the lock groove 301 z (referredto as reference position) as a reference in the clockwise direction arestipulated as follows. The first lens claw 301 d is disposed between159° to 212° with the reference position as a start point. The secondlens claw 301 e is disposed between 256° to 318° with the referenceposition as a start point. The third lens claw 301 f is disposed between54° to 107° with the reference position as a start point.

Now, when viewing the lens mount 301 from the optical axis direction inthe present embodiment, of the multiple bayonet claws, the second lensclaw 301 e overlaps a first lens mount center line 3005 that extends inthe vertical direction of the lens mount 301, in the radial direction ofthe lens mount 301. Also, when viewing the lens mount 301 from the rearface side and front face side in the present embodiment, of the multiplebayonet claws, the third lens claw 301 f overlaps the first lens mountcenter line 3005 in the radial direction of the lens mount 301.

Note that the first lens mount center line 3005 is a line that, in anormal position of the camera body 10 to which the first lens 100 hasbeen mounted, extends in the gravitational direction and the oppositedirection from the gravitational direction, from the center (opticalaxis) of the camera mount 301. In other words, the first lens mountcenter line 3005 is a vertical line that passes through a center of thelens mount 301 and is orthogonal to the center axis of the lens mount301 when the camera body 10 to which the first lens 100 is attached isplaced on a horizontal plane. As opposed to this, a line that, in avertical position of the camera body 10 to which the first lens 100 hasbeen mounted, extends in the gravitational direction and the oppositedirection from the gravitational direction, from the center (opticalaxis) of the camera mount 301, is a second lens mount center line 3006.This second lens mount center line 3006 overlaps the lock groove 301 zand first lens claw 301 d in the radial direction of the lens mount 301.Note that the first lens mount center line 3005 and second lens mountcenter line 3006 are mutually orthogonal.

In the present embodiment, when the first lens 100 is mounted to thecamera body 10, the second lens claw 301 e and third lens claw 301 foverlap the first lens mount center line 3005 in the radial direction ofthe lens mount 301, as illustrated in FIG. 7A. According to thisconfiguration, when the first lens 100 is mounted to the camera body 10,the first lens mount center line 3005 overlaps two positions of engagingpositions between lens claws and camera claws. In this case for example,in the normal position of the imaging apparatus 10 regarding which thefrequency of usage is highest, looseness (bowing) of the first lens 100mounted to the camera body 10 in the gravitational direction can bereduced.

Also, in the present embodiment, when the first lens 100 is mounted tothe camera body 10, the first lens claw 301 d overlaps the second lensmount center line 3006 in the radial direction of the lens mount 301, asillustrated in FIG. 7A. According to this configuration, when the firstlens 100 is mounted to the camera body 10 the second lens mount centerline 3006 overlaps the position where the first lens claw 301 d and thefirst camera claw 201 a engage. In this case for example, in thevertical position of the imaging apparatus as well, looseness (bowing)of the first lens 100 mounted to the camera body 10 in the gravitationaldirection can be reduced.

Also, in a state where the first lens 100 is mounted to the camera body10, the second camera mount center line 3002 and second lens mountcenter line 3006 overlap a lock region where the lock pin 202 and lockgroove 301 z are fit, as described above. According to thisconfiguration, in the vertical position of the camera body 10, theengaging position of the first camera claw 201 a and first lens claw 301d and the above-described lock region overlap the mount center linesextending in the gravitational direction and the opposite directionthereof. According to this configuration, in the vertical position ofthe imaging apparatus, for example, looseness (bowing) of the first lens100 mounted to the camera body 10 in the gravitational direction can besuppressed even more effectively.

Configuration of Contact Pins in Camera Body 10

The configuration of the contact pins provided to the camera body 10side will be described with reference to FIGS. 8A and 8B below. FIGS. 8Aand 8B are external perspective views viewing a camera mount 201according to the embodiment of the present invention from the front faceside (subject side). FIG. 8A is an external view of the camera mount 201from the optical axis direction, and FIG. 8B is an external perspectiveview of the camera mount 201 from above.

The contact holding member 203, and contact pins 203 a through 203 k and203 m that are held by the contact holding member 203 are disposedfollowing the circumferential direction of the camera mount 201 on theinner side of the camera mount 201, as illustrated in FIG. 8A. An arrayline on which the contact points are disposed is illustrated in FIG. 8Aas an array line 3007.

The contact pins 203 a through 203 k and 203 m are movable pins that canadvance and retreat (protrude and retract) in a direction parallel tothe optical axis 3000, and are biased from behind toward the first lens100 side by leaf springs (omitted from illustration). As describedabove, the contact pins 203 a through 203 k and 203 m have the functionsof the above-described respective terminals, and the part numerals bywhich the contact pins are denoted are the same as those of theterminals, to facilitate description.

As illustrated in FIG. 8B, out of the contact pins 203 a through 203 kand 203 m, the contact pins 203 a, 203 b, 203 c, and 203 d are higher inthe direction parallel to the optical axis 3000 (toward the front face)as compared to the other contact pins. Although the above-describedconfiguration is realized by differing the amount of protrusion from thecontact holding member 203 in the optical axis direction in the presentembodiment, a configuration may be employed where this is realized bydiffering the amount of protrusion of the contact pins from the contactholding member 203.

Generally, in a case of employing the bayonet coupling method andattaching/detaching an interchangeable lens to/from a camera, thecontact pins at the camera side and the contact face on the lens sideslide over each other. For example, at the camera side, contact pinsother than the contact pin situated at the edge in the rotationaldirection to complete mounting of the interchangeable lens slide overone or another contact face provided to the lens side. Accordingly, themore times the camera accessory is attached/detached to/from the camera,the more the contact pins and contact faces are worn.

The greater the number of terminals is, the more pronounced this problemis, and the number of times of sliding between contact pins and contactfaces increases. Voltage drop increases due to the contact impedance ofthe terminals rising due to wearing of the contact pins and contactfaces, and the interchangeable lens may malfunction, for example, due tothe voltage dropping below the allowable voltage range for operation ofthe electric circuits.

Accordingly, in the present embodiment, the contact height of thecamera-side contact pins and the interchangeable-lens-side contact facesare differed in a direction parallel to the optical axis 3000, betweenan upper tier and a lower tier. Specifically, the contact holding member203 has a step (height level difference) in a direction parallel to theoptical axis 3000, with the contact pins 203 a through 203 d beingprovided to the upper tier, and the contact pins 203 e through 203 k and203 m being provided to the lower tier. The contact face holding member303 also is stepped in a direction parallel to the optical axis 3001,with the contact pins 303 a through 303 d provided to the lower tier,and the contact pins 303 e through 303 k and 303 m provided to the uppertier.

The upper tier of the contact holding member 203 at the camera mount 201side is a tier protruding toward the front face side (subject side) ofthe first lens 100 when the first lens 100 is mounted to the camera body10. The lower tier of the contact holding member 203 is a tier recessedtoward the rear face side (imaging sensor 11 side) of the camera body10. The upper tier of the contact face holding member 303 at the lensmount 301 side is a tier protruding toward the rear face side (imagingsensor 11 side) of the first lens 100 when the first lens 100 is mountedto the camera body 10. The lower tier of the contact face holding member303 is a tier recessed to the front face side (subject side) of thecamera body 10.

In a case where the lens mount 301 is mounted to the camera mount 201,the contact pins provided to the upper tier side of the contact holdingmember 203 and the contact faces provided to the lower tier side of thecontact face holding member 303 are electrically in contact amongcorresponding terminals. Also, in a case where the lens mount 301 ismounted to the camera mount 201, the contact pins provided to the lowertier side of the contact holding member 203 and the contact facesprovided to the upper tier side of the contact face holding member 303are electrically in contact among corresponding terminals. Accordingly,the steps at the camera mount 201 side and lens mount 301 side have amutually engageable shape, so when mounting the lens mount 301 to thecamera mount face A, the contact pins at the camera side and contactfaces at the lens side that are provided to different steps do not comeinto contact.

According to this configuration, when relatively rotating the first lens100 as to the camera body 10 from the mounting start state to themounting completed state, the contact pins 203 e through 203 k and 203 mdo not come into contact with the contact faces 303 a through 303 d.Also, when relatively rotating the first lens 100 as to the camera body10 from the mounting completed state to the mounting start state, thecontact pins 203 e through 203 k and 203 m do not come into contact withthe contact faces 303 a through 303 d. That is to say, the number oftimes of sliding between contact pins and contact faces can be reducedat both the camera mount 201 side and lens mount 301 side.

Note that the contact pins at the camera body 10 side and the contactfaces at the first lens 100 side are all in a non-contact state in themounting start state of the first lens 100 as to the camera body 10, soshort-circuiting among terminals before completion of mounting of thefirst lens 100 can be prevented.

Configuration of Contact Faces in First Lens 100

The following is a description regarding the configuration of thecontact faces provided to the first lens 100 side, with reference toFIGS. 9A and 9B. FIGS. 9A and 9B are external perspective views of thelens mount 301 according to the embodiment of the present invention, asviewed from the side to which the camera mount 201 is mounted (rear faceside). FIG. 9A is an external view of the lens mount 301 from theoptical axis direction, and FIG. 9B is an external perspective view ofthe lens mount 301 from above.

The contact face holding member 303, and contact faces 303 a through 303k and 303 m that are held by the contact face holding member 303 aredisposed on the inner side of the lens mount 301, following thecircumferential direction of the lens mount 301, as illustrated in FIG.9A. An array line on which the contact points are disposed isillustrated in FIG. 9A as an array line 3008. As described above, thecontact faces 303 a through 303 k and 303 m have the functions of theabove-described respective terminals, and the part numerals by which thecontact faces are denoted are the same as those of the terminals, tofacilitate description.

As illustrated in FIG. 9B, out of the contact faces 303 a through 303 kand 303 m, the contact faces 303 a, 303 b, 303 c, and 303 d are lower inthe direction parallel to the optical axis 3001 as compared to the othercontact faces. The above-described configuration is realized bydiffering the amount of protrusion of the contact face holding member303 in the optical axis direction in the present embodiment.

According to the configuration described above, when relatively rotatingthe first lens 100 as to the camera body 10 from the mounting startstate to the mounting completed state, the contact faces 303 a through303 d do not come into contact with the contact pins 203 e through 203 kand 203 m. Also, when relatively rotating the first lens 100 as to thecamera body 10 from the mounting completed state to the mounting startstate, the contact faces 303 a through 303 d do not come into contactwith the contact pins 203 e through 203 k and 203 m. That is to say, thenumber of times of sliding between contact pins and contact faces can bereduced at both the camera mount 201 side and lens mount 301 side.

Also, the contact face holding member 303 has a first guiding inclinedface 303 n and a second guiding inclined face 303 p for drawingcorresponding contact pins toward the rear face direction (imagingsensor 11 side) when mounting the first lens 100 to the camera body 10,as illustrated in FIG. 9B. According to this configuration, the contactpressure of the contact pins provided to the camera body 10 side as tothe contact face holding member 303 gradually changes, wherebydeformation and wear of the contact pins provided to the camera body 10can be reduced.

Operations of Attaching First Lens 100 to Camera Body 10

Next, the operations at the time of mounting the first lens 100 to thecamera body 10 will be described with reference to FIGS. 10A and 10B.FIGS. 10A and 10B are diagrams exemplarily describing a contact statebetween terminals on the camera body 10 and first lens 100 according tothe embodiment of the present invention. FIG. 10A is a diagram fordescribing the contact state of the terminals in the mounting startstate where mounting of the first lens 100 to the camera body 10 hasbeen started. FIG. 10B is a diagram for describing the contact state ofthe terminals in the mounting completed state where mounting of thefirst lens 100 to the camera body 10 has been completed. Note that inthe state illustrated in FIG. 10A, the contact pins 203 a and 203 b atthe camera mount 201 side in the optical axis direction overlap thecontact faces 303 m and 303 k at the lens mount face B side. However,the height of the contact holding member 203 and the contact faceholding member 303 in the direction parallel with the optical axis ismade to differ for each region, as described above, none of the contactpins and contact faces come into contact in the state illustrated inFIG. 10A.

The state illustrated in FIG. 10B is a state where the first lens 100has been rotated by generally 60° as to the camera body 10 from thestate illustrated in FIG. 10A toward the direction indicated by thearrow (see FIG. 10A). That is to say, in the present embodiment, therelative rotational angle of the camera body 10 and first lens 100 fromthe mounting start state to the mounting completed state is generally60°. Note that in the state illustrated in FIG. 10B, the lock pin 202 isin the state of fitting the lock groove 301 z (locked).

Rotating the first lens 100 by generally 60° as to the camera body 10guides the first lens claw 301 d into the rear face side (imaging sensor11 side) of the first camera claw 201 a and the two are engaged witheach other in the optical axis direction. Also, in this state, thesecond lens claw 301 e is guided into the rear face side (imaging sensor11 side) of the second camera claw 201 b, and these are engaged witheach other in the optical axis direction. Also, in the is state, thethird lens claw 301 f is guided into the rear face side (imaging sensor11 side) of the third camera claw 201 c, and these are engaged with eachother in the optical axis direction. Further, the positions of the lensclaws provided to the first lens 100 are positioned by being biasedtoward the rear face side by the lens mount biasing member 206 providedto the camera mount 201 side, thereby coupling the camera body 10 andthe first lens 100.

Also, the contact pins at the camera body 10 side are pressed toward therear face side (imaging sensor 11 side) by the first guiding inclinedface 303 n and second guiding inclined face 303 p. The contact pins ofthe camera body 10 come into contact with corresponding places on thecontact faces 303 a through 303 k and 303 m at the lens mount 301 sidein a state of being pressed, and come into contact with the respectivelycorresponding contact faces in the mounting completed state. Note thatat this time, the contact pin 203 m provided to the camera mount 201side and the contact face 303 e provided to the lens mount 301 startcoming into contact first.

Basic Configuration of Conversion Adapter

Next, the basic configuration of a conversion adapter (adapter device)that is a camera accessory mountable to the camera mount 201 of theabove-described camera body 10 will be described with reference to FIGS.11A through 12B. FIGS. 11A and 11B are diagrams describing the firstconversion adapter 40 that is mountable to the camera body 10, and asecond lens unit 50. FIG. 11A illustrates an external perspective viewof the second lens unit 50 having been mounted to the camera body 10 viathe first conversion adapter 40. FIG. 11B illustrates an externalperspective view of a state where the camera body 10, first conversionadapter 40, and second lens unit 50 have each been detached. Note thatthe second lens unit (hereinafter referred to as second lens) 50 has alens mount 501 that is short in flange focal distance, but has the samemount diameter as the camera mount 201, as to the camera body 10. Thatis to say, the second lens 50 has the same mount diameter as theabove-described first lens 100, but unlike the first lens 100, is acamera accessory that is not compatible with direct mounting to thecamera body 10.

FIGS. 12A and 12B are diagrams for describing the second conversionadapter 70 that is mountable to a camera body 60 and the first lens 100.FIG. 12A illustrates an external perspective view of a state where thefirst lens 100 is mounted to the camera body 60 via the secondconversion adapter 70, and FIG. 12B illustrates an external perspectiveview where the camera body 60, second conversion adapter 70, and firstlens 100 have each been detached.

Now, in a case where a lens unit with a long flange focal distance isdirectly mounted to an imaging apparatus with a short flange focaldistance, trouble will occur such as the focal point not being formed atan accurate position or the like, and imaging a subject in this way willresult in an unnatural image being obtained. For example, the aboveproblem will occur if the second lens unit 50 that has a long flangefocal distance is mounted to the above-described camera body 10.

In the same way, in a case where a lens unit with a short flange focaldistance is directly mounted to an imaging apparatus with a long flangefocal distance, trouble will occur such as the focal point not beingformed at an accurate position or the like, and imaging a subject inthis way will result in an unnatural image being obtained. For example,the above problem will occur if the first lens 100 that has a shortflange focal distance is mounted to the camera body 60 serving as asecond imaging apparatus that has a longer flange focal distance thanthe above-described camera body 10.

Particularly, the camera body 10 and camera body 60, and the first lens100 and second lens 50, have the same mount diameter, it is difficultfor a user to judge which imaging apparatuses and which lens units haveflange focal distances that are compatible for direct mounting.

Accordingly, it is preferable that only lens units that are compatiblecan be directly mounted to a certain imaging apparatus, so that imagingapparatuses and lens units that have mutually incompatible flange focaldistances are not erroneously directly mounted.

Also, in a case of mounting an incompatible lens unit to an imagingapparatus, a conversion adapter needs to be interposed between the twoto adjust the flange focal distance. However, in a case where one sideof the conversion adapter is mounted to the imaging apparatus and a lensunit compatible with direct mounting to the imaging apparatus is mountedto the other side of the conversion adapter, the focal point may not beaccurately formed, as described above. Accordingly, the one side andother side of the conversion adapter preferably have configurations torestrict imaging apparatuses and camera accessories that are directlymountable.

Specifically, in a case of mounting a lens unit having a long flangefocal distance to an imaging apparatus having a short flange focaldistance, a conversion adapter is preferable where one end side is onlymountable to this imaging apparatus, and the other end side is onlymountable to this lens unit. Also, in a case of mounting a lens unithaving a short flange focal distance to an imaging apparatus having along flange focal distance, a conversion adapter is preferable where oneend side is only mountable to this imaging apparatus, and the other endside is only mountable to this lens unit.

The first conversion adapter 40 has the lens mount 1301 attached to anadapter barrel 40 a by fastening screws (omitted from illustration), atone end side in the optical axis direction. This lens mount 1301 is anaccessory mount that is detachable from the camera mount 201 provided tothe camera body 10 described above.

A camera mount 1401 is attached to the adapter barrel 40 a by fasteningscrews (omitted from illustration), at the other end side of the firstconversion adapter 40 in the optical axis direction. This camera mount1401 is a camera mount that is detachable from the lens mount 501 of thesecond lens 50. Note that the camera mount 1401 of the first conversionadapter 40 is attached so that the imaging plane of the imaging sensor11 of the will be situated at a position corresponding to the flangefocal distance of the second lens 50.

The second conversion adapter 70 has the lens mount 1501 attached to anadapter barrel 70 a by fastening screws (omitted from illustration), atone end side in the optical axis direction. This lens mount 1501 is anaccessory mount that is detachable from the camera mount 401 provided tothe camera body 60.

The camera mount 1201 is attached to the adapter barrel 70 a byfastening screws (omitted from illustration), at the other end side ofthe second conversion adapter 70 in the optical axis direction. Thiscamera mount 1201 is a camera mount that is detachable from the lensmount 301 of the first lens 100, as described above.

Note that a first optical member 701 a and a second optical member 701 bare provided to the second conversion adapter 70, between the adapterbarrel 70 a and the lens mount 1501 in the optical axis direction. Thefirst optical member 701 a and second optical member 701 b enable thesecond conversion adapter 70 to extend length of the flange focaldistance of the first lens 100 in accordance with the imaging plane ofthe imaging sensor disposed in the camera body 60. While the opticalmembers have been illustrated as two lenses for the sake of convenience,this is not restrictive.

Configuration of First Conversion Adapter 40

Next, the angles (phases) at which bayonet claws are disposed on thecircumferential direction of the camera mount and lens mount of thefirst conversion adapter 40 will be described with reference to FIG. 13Athrough FIG. 17D. FIGS. 13A through 13C are diagrams for exemplarilydescribing displacement angles of bayonet claws in the camera mount 1401provided on one end of the first conversion adapter 40. FIG. 13A is adiagram illustrating angle ranges that camera claws and camera recessesoccupy in the circumferential direction of the camera mount 1401 withthe lock pin 1401 z as a reference, as viewed from the rear face side(camera body 10 side). FIG. 13B is a diagram illustrating angle rangesthat multiple camera claws 1401 a through 1401 c occupy in thecircumferential direction of the camera mount 1401, as viewed from therear face side (camera body 10 side). FIG. 13C is a cross-sectionaldiagram taken along cross-section XIIIB-XIIIB in FIG. 13B.

The first conversion adapter 40 is a mount adapter used for mounting thesecond lens unit 50 that has a long flange focal distance to the camerabody 10 that has a short flange focal distance. Accordingly, it ispreferable for the first conversion adapter 40 to be configured suchthat the camera body 60 that has a long flange focal distance cannot bedirectly mounted to the lens mount 1301, and the first lens 100 that hasa short flange focal distance cannot be directly mounted to the cameramount 1401. According to this configuration, the positional relation ofclaws and recesses can be satisfied so that the lens mount 1301 providedto one end (first end) of the first conversion adapter 40 and the cameramount 1401 provided to the other end (second end) cannot each bedirectly mounted.

A first camera claw 1401 a, second camera claw 1401 b, and third cameraclaw 1401 c, are provided in order, to the camera mount 1401 in thecircumferential direction (inner radial direction). When viewing thecamera mount 1401 from the rear face side as illustrated in FIG. 13A,the camera claw that is provided at a position farthest from the lockpin 1401 z is the first camera claw 1401 a. The second camera claw 1401b and third camera claw 1401 c are then consecutively provided in orderfrom the first camera claw 1401 a in a clockwise direction.

Also, recesses which are a first camera recess 1401 d, second camerarecess 1401 e, and third camera recess 1401 f are provided in order, tothe camera mount 1401 in the circumferential direction (inner radialdirection). When viewing the camera mount 1401 from the rear face sideas illustrated in FIG. 13A, the recess that is provided at a positionnearest to the lock pin 1401 z is the second camera recess 1401 e. Thethird camera recess 1401 f and first camera recess 1401 d are thenconsecutively provided in order from the second camera recess 1401 e ina clockwise direction.

As illustrated in FIG. 13C, a fitting member 1401 x that restrictsmovement of the camera accessory in a direction parallel to the opticalaxis when the camera accessory is mounted, is provided to the cameramount 1401 side. In the present embodiment, the diameter of the fittingmember 1401 x in a direction orthogonal to the optical axis at thecamera mount 1401 side is the mount diameter.

The way of bayonet coupling of the first conversion adapter 40 andsecond lens 50 is the generally the same as the way of bayonet couplingof the camera body 10 and first lens 100 described above, so descriptionwill be omitted.

Note that the end portions of the camera claws 1401 a, 1401 b, and 1401c, in the circumferential direction, will be referred to as first endportion 1401 a 1, second end portion 1401 a 2, third end portion 1401 b1, fourth end portion 1401 b 2, fifth end portion 1401 c 1, and endportion 1401 c 2, for the sake of description. The end portions aredenoted with part numerals in order from the first camera claw 1401 a inthe clockwise direction, when viewing the camera mount 1401 from therear face side, as described above.

As illustrated in FIG. 13A, the angles that the camera claws and camerarecesses occupy in the circumferential direction of the camera mount1401 (angle ranges) in the first conversion adapter 40 according to thepresent embodiment are stipulated as follows. For the first camera claw1401 a, the angle θ1=56°, for the second camera claw 1401 b, the angleθ2=62°, and for the third camera claw 1401 c, the angle θ3=62°. Also,for the first camera recess 1401 d, the angle is 57°, for the secondcamera recess 1401 e, the angle is 66°, and for the third camera recess1401 f, the angle is 57°. That is to say the camera mount 1401 hasdifferent angles for the camera claws with respect to theabove-described camera mount 201 of the camera body 10, but the anglesof the camera recesses are the same.

Also, when viewing the camera claws from the rear face side of the firstconversion adapter 40, the angles where the camera claws are disposed onthe circumferential direction of the camera mount 1401 with the positionof the lock pin 402 (referred to as reference position) as a referenceare stipulated as follows. The first camera claw 1401 a is disposedbetween 159° to 215° with the reference position as a start point. Thesecond camera claw 1401 b is disposed between 272° to 334° with thereference position as a start point. The third camera claw 1401 c isdisposed between 40° to 102° with the reference position as a startpoint.

Next, FIGS. 14A and 14B are diagrams exemplarily describing angles ofdisposing the bayonet claws on the lens mount 1301 provided to the otherend of the first conversion adapter 40. FIG. 14A is a diagramillustrating angle ranges that camera claws and camera recesses occupyin the circumferential direction of the camera mount 1401 with the lockgroove 1301 z as a reference, as viewed from the rear face side. FIG.14B is a diagram illustrating angle ranges that multiple lens recesses1301 a through 1301 c occupy in the circumferential direction of thecamera mount 1301, as viewed from the rear face side.

The angles (angle ranges) that the lens recesses occupy in thecircumferential direction of the lens mount 1301 are, represented by θ4as the angle of the first lens recess 1301 a and θ5 as the angle of thesecond lens recess 1301 b, as illustrated in FIG. 14B. Note that theangle so disposing the claws and recesses on the lens mount 1301 of thefirst conversion adapter 40 is the same as the lens mount 301 of thefirst lens 100 described above, and accordingly description will beomitted.

The angles of the claws and recesses in the circumferential direction,on the lens mount 1301 and camera mount 1401 provided to the firstconversion adapter 40, will be compared. For example, at the lens mount1301 side, the angle θ5 of the second lens recess 1301 b having thesmallest angle is 44°, whereas, at the camera mount 1401 side, the angleθ1 of first camera claw 1401 a having the smallest angle is 56°. That isto say, the claw having the smallest angle at the camera mount 1401 sideis larger than the recess having the smallest angle at the lens mount1301 side (θ5<θ1). In this case, of the recesses on the lens mount 1301side and the claws on the camera mount 1401 side, at least one or morelens recess and camera claws will interfere with each other.Accordingly, even if an attempt is made to mount the lens unit to thecamera body so that the optical axis at the camera mount 1401 side andlens mount 1301 side are generally parallel, the claws and recessesinterfere, so the lens unit cannot be mounted to the camera body.

However, if only one claw and recess are interfering, there may be caseswhere claws of the camera mount side can be inserted into recesses ofthe lens mount side. FIGS. 15A and 15B are diagrams exemplarilydescribing a mounting method of a predetermined imaging apparatus 1000and a predetermined lens unit 2000 having claws and recesses thatinterfere with each other. FIG. 15A is a diagram exemplarily describinga frontal view of partway through mounting a predetermined lens unit toa predetermined imaging apparatus that have claws and recesses thatinterfere with each other. FIG. 15B is a cross-sectional view takenalong cross-section XVB-XVB in FIG. 15A.

For example, in a state where the optical axis of the lens mount side isobliquely inclined as to the optical axis of the camera mount side, oneend of a camera claw is inserted into a lens recess, and from thisstate, the lens mount and camera mount are rotated relatively to eachother, as illustrated in FIGS. 15A and 15B. In this case, even if thecamera claws and lens recesses originally interfere with each other,this interference with each other is resolved during the relativerotation of the lens mount and camera mount, and transition can be madeto a state where the camera claw is inserted into this lens recess. Inthis case, if there are no other camera claws and lens recessesinterfering, the lens unit can be mounted to the camera body.

Accordingly, the claws and recesses on the lens mount 1301 side andcamera mount 1401 side are disposed such that the angle of apredetermined lens recess adjacent to a reference lens claw is smallerthan the angle of two camera claws adjacent to a reference camerarecess. Specifically, in the present embodiment, the angles θ4 and θ5 ofthe first lens recess 1301 a and second lens recess 1301 b adjacent tothe first lens claw 1301 d are smaller than the angles θ1 and 02 of thefirst camera claw 1401 a and second camera claw 1401 b adjacent to thefirst camera recess 1401 d. That is to say, θ4 (52°) is smaller than θ1(56°), and θ5 (44°) is smaller than θ2 (62°) (θ4<θ1, θ5<θ2).Accordingly, even if an attempt is made to insert the first lens claw1301 d into the first camera recess 1401 d, the second lens claw 1301 einterferes with the second camera claw 1401 b in a sure manner, as welldoes the third lens claw 1301 f with the first camera claw 1401 a, asillustrated in FIGS. 16A and 16B.

FIGS. 16A and 16B are diagrams exemplarily describing the way in whichclaws interfere with each other when attempting to mount the lens mount1301 side to the camera mount 1401 side according to the embodiment ofthe present invention. FIG. 16A illustrates the way in which the thirdlens claw 1301 f and the first camera claw 1401 a interfere, and FIG.16B illustrates the way in which the second lens claw 1301 e and thesecond camera claw 1401 b interfere.

As described above, incompatible lens units and imaging apparatuses, andthe mount portions of conversion adapters are configured so that twoclaws of each other out of the claws that an incompatible lens unit andimaging apparatus have interfere with each other in the presentembodiment. According to this configuration, the risk of an incompatiblelens unit being erroneously mounted to an imaging apparatus, or anincompatible lens unit and imaging apparatus being erroneously mountedto mount units provided to both ends of a conversion adapter, can bereduced.

However, even in a case where the above conditions are satisfied, theremay be cases where, when attempting to insert three claws intoincompatible recesses, for example, two claws are inserted into recessesdepending on the angles of the claws and recesses. Accordingly, thepresent embodiment further takes a configuration where the angles of atleast two adjacent lens recesses are smaller than the angles of allcamera claws. Specifically, in the present embodiment, the angles θ4 andθ5 of the first lens recess 1301 a and second lens recess 1301 b in thecircumferential direction are smaller than the angles θ1 through θ3 ofthe first through third camera claws 1401 a through 1401 c in thecircumferential direction. That is to say, the relation between theclaws and recesses at the lens mount 1301 side and the camera mount 1401side according to the present embodiment satisfy θ4<θ1, θ4<θ2, θ4<θ3,θ5<θ1, θ5<θ2, and θ5<θ3.

FIGS. 17A through 17D is a diagram exemplarily describing a case ofattempting to insert incompatible claws into recesses at the lens mount1301 side and camera mount 1401 side according to the embodiment of thepresent invention. FIG. 17A illustrates the way in which the third lensclaw 1301 f and third camera claw 1401 c interfere in a case ofattempting to insert the first lens claw 1301 d into the third camerarecess 1401 f. FIG. 17B illustrates the way in which second lens claw1301 e and first camera claw 1401 a interfere in a case of attempting toinsert the first lens claw 1301 d into the third camera recess 1401 f.FIG. 17C illustrates the way in which the third lens claw 1301 f andsecond camera claw 1401 b interfere in a case of attempting to insertthe first lens claw 1301 d into the second camera recess 1401 e. FIG.17D illustrates the way in which the second lens claw 1301 e and thirdcamera claw 1401 c interfere in a case of attempting to insert the firstlens claw 1301 d into the second camera recess 1401 e.

As illustrated in FIGS. 17A through 17D, the lens claws and camera clawsinterfere in at least two places in the present embodiment, regardlessof the relative rotational angle of the lens mount 1301 and camera mount1401. According to this configuration, erroneous mounting of a lens unitand conversion adapter having the lens mount 301 or the lens mount 1301to an imaging apparatus and conversion adapter having the camera mount401 or the camera mount 1401 can be prevented even more effectively.

Configuration of Second Conversion Adapter 70

Next, the angles (phases) at which bayonet claws are disposed on thecircumferential direction of the camera mount and lens mount of thesecond conversion adapter 70 will be described with reference to FIGS.18A through 21D.

The second conversion adapter 70 is a mount adapter used for mountingthe first lens 100 that has a short flange focal distance to the camerabody 60 that has a long flange focal distance. The lens mount 1501 isprovided at one end (third end) side of the second conversion adapter70, and the camera mount 1201 is provided at the other end (fourth end).Note that the camera mount 1201 of the second conversion adapter 70 hasthe same configuration as the camera mount 201 of the camera body 10that is the first imaging apparatus described above. Also, the lensmount 1501 of the second conversion adapter 70 has the sameconfiguration as the lens mount 501 of the second lens 50 describedabove.

Accordingly, it is preferable for the second conversion adapter 70 to beconfigured such that the camera body 10 that has a short flange focaldistance cannot be directly mounted to the lens mount 1501, and thesecond lens 50 that has a long flange focal distance cannot be directlymounted to the camera mount 1201. This configuration can be realized bysatisfying the positional relation of claws and recesses so that thelens mount 1501 provided to one end (third end) of the second conversionadapter 70 and the camera mount 1201 provided to the other end (fourthend) cannot each be directly mounted.

FIGS. 18A and 18B are diagrams exemplarily describing angles ofdisposing bayonet claws in the camera mount 1201 provided on one end ofthe second conversion adapter 70. FIG. 18A is a diagram illustratingangle ranges that camera claws and camera recesses occupy in thecircumferential direction of the camera mount 1201 with the lock pin 202as a reference, as viewed from the rear face side. FIG. 18B is a diagramillustrating angle ranges that, regarding multiple camera claws 1201 athrough 1201 c, the claws occupy in the circumferential direction of thecamera mount 1201, as viewed from the rear face side. Note that theangles of disposing the claws and recesses on the camera mount 1201 ofthe second conversion adapter 70 are the same as the camera mount 1201of the camera body 10 described earlier, so description will be omitted.

As illustrated in FIG. 18B, the angle from the sixth end 1201 c 2 of thethird camera claw 1201 c to the third end 1201 b 1 of the second cameraclaw 1201 b, in the circumferential direction of the camera mount 1201including the first camera claw 1201 a, is θ6 (162°). The angle from thesecond end 1201 a 2 of the first camera claw 1201 a to the fifth end1201 c 1 of the third camera claw 1201 c, in the circumferentialdirection of the camera mount 1201 including the second camera claw 1201b, is θ7 (1630). The angle from the fourth end 1201 b 2 of the secondcamera claw 1201 b to the first end 1201 a 1 of the first camera claw1201 a, in the circumferential direction of the camera mount 1201including the third camera claw 1201 c, is θ8 (215°).

Next, FIGS. 19A through 19C are diagrams exemplarily describing angle sodisposing bayonet claws in a lens mount 1501 provided on the other endof the second conversion adapter 70. FIG. 19A is a diagram illustratingangle ranges that lens claws and lens recesses occupy in thecircumferential direction of the lens mount 1501 with the lock pin 1501z as a reference, as viewed from the rear face side. FIG. 19B is adiagram illustrating angle ranges where recesses are provided regardingthe multiple lens recesses 1501 a through 1501 c in the circumferentialdirection of the lens mount 1501, as viewed from the rear face side.FIG. 19C is a cross-sectional diagram taken along cross-sectionXIXC-XIXC in FIG. 19B.

A first lens claw 1501 d, second lens claw 1501 e, and third lens claw1501 f, are provided in order, to the camera mount 1501 in thecircumferential direction (inner radial direction). Note that in a caseof viewing the lens mount 1501 from the rear face side as illustrated inFIG. 19A, the lens claw that is provided at a position farthest from thelock groove 1501 z is the first lens claw 1501 d. The second lens claw1501 e and third lens claw 1501 f are then consecutively provided inorder from the first lens claw 1501 d in a clockwise direction.

Also, recesses which are a first lens recess 1501 a, second lens recess1501 b, and third lens recess 1501 c are provided in order, to the lensmount 1501 in the circumferential direction (inner radial direction).Note that in a case of viewing the lens mount 1501 from the rear faceside as illustrated in FIG. 19A, the recess that is provided at aposition nearest to the lock groove 1501 z is the third lens recess 1501c. The first lens recess 1501 a and second lens recess 1501 b are thenconsecutively provided in order from the third lens recess 1501 c in aclockwise direction.

Note that the end portions of the lens claws 1501 d, 1501 e, and 1501 f,in the circumferential direction, will be referred to as first endportion 1501 d 1, second end portion 1501 d 2, third end portion 1501 e1, fourth end portion 1501 e 2, fifth end portion 1501 fi, and sixth endportion 1501 f 2, for the sake of description. The end portions aredenoted with part numerals in order from the first lens claw 1501 d inthe clockwise direction, when viewing the lens mount 1501 from the rearface side, as described above.

As illustrated in FIG. 19A, the angles that the lens claws and lensrecesses occupy in the circumferential direction of the lens mount 1501(angle ranges) are stipulated as follows. The angle of the first lensclaw 1501 d is 53°, the angle of the second lens claw 1501 e is 62°, andthe angle of the third lens claw 1501 f is 53°. That is to say, theangles of the lens claws on the lens mount 1501 side are the same as theangles of the lens claws on the lens mount 1301 side described earlier.

On the other hand, the angles of the lens recesses at the lens mount1501 side differ from the angles of the lens recesses at the lens mount1301 side described above. Specifically, the angle of the first lensrecess 1501 a is 60°, the angle of the second lens recess 1501 b is 66°,and the angle of the third lens recess 1501 c is 66°.

Also, when viewing the lens claws from the rear face side of the camerabody 10, the angles in the clockwise direction where the lens claws aredisposed on the circumferential direction of the lens mount 1501 withthe position of the lock groove 1501 z (referred to as referenceposition) as a reference are stipulated as follows. The first lens claw1501 d is disposed between 157° to 210° with the reference position as astart point. The second lens claw 1501 e is disposed between 276° to338° with the reference position as a start point. The third lens claw1501 f is disposed between 44° to 97° with the reference position as astart point.

As illustrated in FIG. 19C, a fitting member 1501 x that restrictsmovement of the imaging apparatus in a direction parallel to the opticalaxis when mounted to the imaging apparatus is provided to the lens mount1501 side. In the present embodiment, the diameter of the fitting member1501 x in a direction orthogonal to the optical axis at the camera mount1501 side is the mount diameter. The mount diameters of the cameramounts and lens mounts described above are generally the same length.

As illustrated in FIG. 19B, the angle from the fifth end 1501 f 1 of thethird lens claw 1501 f to the second end 1501 d 2 of the second lensclaw 1501 d, in the circumferential direction of the lens mount 1501including the first lens recess 1501 a, is θ9 (166°). The angle from thefirst end 1501 d 1 of the first lens claw 1501 d to the fourth end 1501e 2 of the second lens claw 1501 e, in the circumferential direction ofthe lens mount 1501 including the second lens recess 1501 b, is θ10(181°). The angle from the third end 1501 e 1 of the second lens claw1501 e to the sixth end 1501 f 2 of the third lens claw 1501 f, in thecircumferential direction of the lens mount 1501 including the thirdlens recess 1501 c, is θ11 (181°).

The angles of the claws and recesses in the circumferential directionwill be compared between the camera mount 1201 and lens mount 1501provided to the second conversion adapter 70. For example, the angle(92°) of the third camera claw at the camera mount 1201 side is largerthan the angles (66°) of the second and third lens recesses 1501 b and1501 c that are the largest angle of the lens recesses at the lens mount1501 side. That is to say, the angle of at least one camera claw at thecamera mount 1201 side is larger than the angle of the lens recesshaving the largest angle at the lens mount 1501 side.

In this case, of the claws at the camera mount 1201 side and recesses atthe lens mount 1501 side, at least one or more camera claw and lensrecess interfere with each other. Accordingly, even if an attempt ismade to mount the lens unit to the camera body so that the optical axisat the camera mount 1201 side and lens mount 1501 side are generallyparallel to each other, the claws and recesses interfere, so the lensunit cannot be mounted to the camera body.

However, if only one claw and recess are interfering, there may be caseswhere claws of the camera mount side can be inserted into recesses ofthe lens mount side, in the same way as the description of the firstconversion adapter made above. For example, there are cases where, in astate where the optical axis of the lens mount side is obliquelyinclined as to the optical axis of the camera mount side, one end of acamera claw is inserted into a lens recess, and the lens mount andcamera mount are rotated relative to each other, and the lens unit canbe mounted to the camera body.

Accordingly, in the present embodiment, the claws and recesses at thecamera mount 1201 side and the lens mount 1501 side are disposed so asto satisfy θ6<θ9 and θ7<θ10 in the circumferential direction. FIGS. 20Aand 20B are diagrams exemplarily describing the way in which clawsinterfere with each other, when attempting to mount a reference claw atthe lens mount 1501 side to a reference recess at the camera mount 1201side according to the embodiment of the present invention. FIG. 20Aillustrates the way in which the third lens claw 1501 f and the thirdcamera claw 1201 c interfere, and FIG. 20B illustrates the way in whichthe second lens claw 1501 e and the third camera claw 1201 c interfere.

As illustrated in FIGS. 20A and 20B, in a case where the reference firstlens claw 1501 d is attempted to be inserted into the reference camerarecess 1201 d, for example, the third camera claw 1201 c interferes withthe second and third lens claws 1501 e and 1501 f.

That is to say, as viewed from the rear face side, the total sum of theangles of one reference lens claw, another lens claw adjacent thereto inthe clockwise direction, and a lens recess situated between these lensclaws, is taken as a first angle. Also, as viewed from the rear faceside, the total sum of the angles of one reference camera recess,another camera recess adjacent thereto in the clockwise direction, and acamera claw portion situated therebetween, is taken as a second angle.Also, as viewed from the rear face side, the total sum of the angles ofone reference lens claw, another lens claw adjacent thereto in thecounterclockwise direction, and a lens recess situated between theselens claws, is taken as a first angle. Also, as viewed from the rearface side, the total sum of the angles of one reference camera recess,another camera recess adjacent thereto in the counterclockwisedirection, and a camera claw portion situated therebetween, is taken asa fourth angle. According to the present embodiment, it is sufficient tolayout the claws and recesses at the camera mount 1201 side and lensmount 1501 side such that the first angle described above is larger thanthe second angle, and the third angle is larger than the fourth angle.

According to this configuration, at least two lens claws and one cameraclaw interfere with each other. Thus, the risk of an incompatible lensunit being erroneously mounted to an imaging apparatus, or anincompatible lens unit and imaging apparatus being erroneously mountedto mount units provided to both ends of a conversion adapter, can bereduced.

However, even in a case where the above conditions are satisfied, theremay be cases where, when attempting to insert three claws intoincompatible recesses, for example, two claws are inserted into recessesdepending on the angles of the claws and recesses. Accordingly, theclaws and recesses at the camera mount 1201 side and lens mount 1501side are disposed in the circumferential direction so as to satisfyθ6<θ9, 06<θ10, 06<θ11, 07<θ9, θ7<θ10, and θ7<θ11. That is to say, asviewed from the rear face side, the total sum of the angles of two clawsother than the reference claw described above, and a lens recesssituated therebetween, is taken as a fifth angle. According to thepresent embodiment, it is sufficient to layout the claws and recesses atthe camera mount 1201 side and lens mount 1501 side such that the secondangle and fourth angle described above are smaller than any of the firstangle, third angle, and fifth angle.

FIGS. 21A through 21D are diagrams exemplarily describing the way inwhich claws interfere with each other, when attempting to mount a clawother than the reference claw at the lens mount 1501 side to a referencerecess at the camera mount 1201 side according to the embodiment of thepresent invention. FIG. 21A illustrates the way in which the first lensclaw 1501 d and the third camera claw 1201 c interfere in a case ofattempting to insert the second lens claw 1501 e into the first camerarecess 1201 d. FIG. 21B illustrates the way in which the third lens claw1501 c and the third camera claw 1201 c interfere in a case ofattempting to insert the second lens claw 1501 e into the first camerarecess 1201 d. FIG. 21C illustrates the way in which the second lensclaw 1501 e and the third camera claw 1201 c interfere in a case ofattempting to insert the third lens claw 1501 f into the first camerarecess 1201 d. FIG. 21D illustrates the way in which the first lens claw1501 d and the third camera claw 1201 c interfere in a case ofattempting to insert the third lens claw 1501 f into the first camerarecess 1201 d.

As illustrated in FIGS. 21A through 21D, at least two lens claws and onecamera claw interfere, regardless of the relative rotation angle of thelens mount 1501 and camera mount 1201 according to the presentembodiment. According to this configuration, erroneous mounting of alens unit and conversion adapter having the lens mount 501 or the lensmount 1501 to an imaging apparatus and conversion adapter having thecamera mount 201 or the camera mount 1201 can be prevented even moreeffectively.

FIG. 22 is a diagram exemplarily describing a state in which clawsprovided to the camera mount 1401 side and lens mount 1501 sideaccording to the embodiment of the present invention are engaged. Notethat FIG. 22 illustrates a state in which the camera mount 401 of thecamera body 60 is engaging the lens mount 501 of the second lens 50. Thefirst lens claw 1501 d can be inserted into the first camera recess 1401d, as illustrated in FIG. 22. Also, the second lens claw 1501 e can beinserted into the second camera recess 1401 e. Further, the third lensclaw 1501 f can be inserted into the third camera recess 1401 f. That isto say, the camera mount 1401 side and the lens mount 1501 side are acombination compatible with being directly mounted to each other. Notethat the camera mount 1201 side and the lens mount 1301 side are acombination compatible to being directly mounted to each other, asillustrated in FIG. 10A.

As described above, the camera mount 401 (1401) corresponding to animaging apparatus that has a long flange focal distance (e.g., thecamera body 60), and the lens mount 501 (1501) corresponding to a lensunit that has a long flange focal distance (e.g., the second lens 50)can be directly mounted to each other. However, the camera mount 201(1201) corresponding to an imaging apparatus having a short flange focaldistance (e.g., the camera body 10) and the lens mount 501 (1501)corresponding to a lens unit that has a long flange focal distance(e.g., the second lens 50) cannot be directly mounted to each other.Also, the camera mount 201 (1201) corresponding to an imaging apparatusthat has a short flange focal distance (e.g., the camera body 10) andthe lens mount 301 (1301) corresponding to a lens unit that has a shortflange focal distance (e.g., the first lens 100) can be directly mountedto each other. However, the camera mount 401 (1401) corresponding to animaging apparatus that has a long flange focal distance (e.g., thecamera body 60) and the lens mount 301 (1301) corresponding to a lensunit that has a short flange focal distance (e.g., the first lens 100)cannot be directly mounted to each other.

Accordingly, an imaging apparatus and camera accessory employing theconfiguration of the above-described embodiment can prevent erroneousmounting of an imaging apparatus and camera accessory that havegenerally the same mount diameter but are not mutually compatible.

Timing of Engaging of Claws and Contact of Contact Points

The timing for engaging of corresponding claws with each other andcontact among contact points when detachably attaching the camera mount201 and lens mount 301 will be described with reference to FIG. 23. FIG.23 is a diagram exemplarily describing timing for engaging of claws witheach other and contact among electrical contact points (terminals) whendetachably attaching the lens mount 301 to the camera mount 201 in theembodiment of the present invention. Note that FIG. 23 illustrates acase of viewing the camera mount 201 and lens mount 301 in theabove-described mounted state, from the rear face side of the camerabody 10.

As illustrated in FIG. 23, in the mounting start state of the lens mount301 as to the camera mount 201, a camera-side contact pin 203 m ispositioned at a first position R1 in the circumferential direction ofthe mount. This contact pin 203 m is the contact pin on the camera mount201 side that first comes into contact with the contact faces at thelens side when mounting the lens mount 301 to the camera mount 201. Thatis to say, the first position R1 indicates a relative angle of themounting start state of the lens mount 301 as to the camera mount 201,where the camera-side contact pin 203 m, which comes into contact withthe contact faces at the accessory side first, is situated.

As described above, none of the contact pins at the camera mount 201side and none of the contact faces of the lens mount 301 side are incontact in this mounting start state. This configuration is realized bythe positions in the optical axis direction where the contact holdingmember 203 and the contact face holding member 303 holding therespective terminals being different, by the contact holding member 203and the contact face holding member 303 being stepped (have the heightlevel difference). Note that the camera-side contact pin 203 m on thecamera mount 201 is disposed at the closest side (starting edge) of thefirst lens 100 as to the camera body 10 at the predetermined tier.

On the other hand, a contact face 303 e is positioned at a secondposition R2 on the lens mount 301 side in FIG. 23. This contact face 303e is the contact face on the lens mount 301 side that first comes intocontact with the contact pins at the camera side when mounting the lensmount 301 to the camera mount 201. Note that the accessory-side contactface 303 e on the lens mount 301 is disposed at the closest (startingedge) of the first lens 100 as to the camera body 10. That is to say,the second position R2 indicates a relative angle of the mounting startstate of the lens mount 301 as to the camera mount 201, where theaccessory-side contact face 303 e, which comes into contact with thecontact pins at the camera side first, is situated.

Note that the first position R1 is synonymous with a position on thecircumferential direction of the mount of a line (first line) connectingthe optical axis and the contact pin 203 m in the radial direction ofthe camera mount 201, when viewing the camera mount 201 from the opticalaxis direction. Also, the second position R2 is synonymous with aposition on the circumferential direction of the mount of a line (secondline) connecting the optical axis and the contact face 303 e in theradial direction of the lens mount 301, when viewing the lens mount 301from the optical axis direction.

As described above, in a mounting completed state of the lens mount 301as to the camera mount 201, the second camera claw 201 b at the cameraside and the second lens claw 301 e at the lens side are engaged witheach other in the optical axis direction. When relatively rotating thecamera mount 201 and lens mount 301 from the mounting start state towardthe mounting completed state, the fourth end portion 201 b 2 side of thesecond camera claw 201 b and the fourth end portion 301 e 2 side of thesecond lens claw 301 e first start engaging.

That is to say, in the present embodiment, in the mounting start stateof the lens mount 301 as to the camera mount 201, the engaging startposition of the second camera claw 201 b and the second lens claw 301 eis included in the shortest range between the first line and the secondline. In other words, in the mounting start state of the first lens 100as to the camera body 10, the engaging start position of at least oneclaw each provided to the camera side and lens side with each other isincluded in an angular range where the terminal 203 m and terminal 303 eare connected in the circumferential direction of the mount.

Then, relatively rotating the mounts from this state starts engagingbetween the camera claws and lens claws, in a state where none of theterminals provided to the camera mount 201 side and terminals providedto the lens mount 301 side, are in contact. In other words, the cameraclaws and lens claws of the camera body 10 and first lens 100 accordingto the present embodiment start engaging at generally the same timing,before any of the contact pins and contact faces start contact with eachother.

According to this configuration, contact of all contact pins and contactfaces with each other is started in a state where the camera claws andlens claws of the camera body 10 and first lens 100 according to thepresent embodiment are engaged, and looseness therebetween has beenreduced. In this case, contact between the contact pins and contactfaces is started in a state where relative looseness between the camerabody 10 and first lens 100 has been suppressed, so friction between thecontact pins and contact faces due to attaching and detaching of themounts can be suppressed.

Although a preferable embodiment of the present invention has beendescribed, the present invention is not restricted to this embodiment,and various modifications and alterations can be made within the scopeof the essence thereof. For example, a case of employing a digitalcamera has been described as an example of the imaging apparatus in theabove-described embodiment, but imaging apparatuses other than digitalcameras, such as digital video cameras, security cameras, and so forth,may be employed in the configuration.

Also, although a case of employing an interchangeable lens and anintermediate accessory (adapter device) such as a conversion adapter andan extension adapter (extension-tube), as an example of the cameraaccessory carrying out the present invention has been described in theembodiment above, this is not restrictive. Any sort of camera accessorymay be employed as long as it is a device that has an accessory mountcapable of directly connecting (coupling) to a camera mount provided tothe above-described imaging apparatuses.

Although a configuration has been described in the above embodimentwhere both of the camera mount and accessory mount corresponding to eachother have a pair of electric terminals through which electricconnection is established in a mutually mounted state, this is notrestrictive. For example, a configuration may be made having electricterminals that do not correspond to each other. For example, aconfiguration may be made where a terminal that the camera body 10 doesnot have is provided to a camera accessory mountable to the camera body10.

Also, although a case has been described in the above embodiment whereeach mount has three claws in the circumferential direction, the numberof claws is not restricted to three, as long as the conditions of theabove-described embodiment are satisfied.

A configuration may be made where each of the three claws provided tothe mounts in the above-described embodiment is further divided. That isto say, a configuration may be made where one claw is one claw groupmade up of multiple claws. A case where a groove is provided to one clawfalls under this, for example. In this case, the ranges of angles ofclaw groups disposed in the circumferential direction of the mounts isthe same as those in the embodiment described above.

Also, although a case has been described in the above embodiment wherethe mount diameter of each mount is the inner diameter of a fittingportion provided to each mount, in a direction orthogonal to the opticalaxis, this is not restrictive. For example, at each mount, an innerdiameter of which the radius is the distance from the center (opticalaxis) of each mount to multiple terminals may be used as the mountdiameter, or an inner diameter of which the radius is the distance fromthe center (optical axis) of each mount to a claw or recess may be usedas the mount diameter.

Although a configuration has been described in the above embodimentwhere a device having one of a camera mount and an accessory mount isactually rotated as to a device having the other mount, therebybayonet-coupling the devices to each other, this is not restrictive. Forexample, a configuration may be employed where a camera mount andaccessory mount are relatively rotated, and the camera mount andaccessory mount are bayonet-coupled. Specifics of this will be describedin detail below.

FIG. 24 is a disassembled perspective view of a mount mechanism 5000according to a modification of the present invention. FIGS. 25A through25C are diagrams for exemplarily describing a non-coupled state of themount mechanism 5000 according to the modification of the presentinvention. FIGS. 26A through 26C are diagrams for exemplarily describinga coupled state of the mount mechanism 5000 according to themodification of the present invention. In FIGS. 24 through 26C, the lensmount that is capable of bayonet-coupling to a movable mount portion5010 of the mount mechanism 5000 is also illustrated, for the same ofdescription. Members that are the same as in the above-describedembodiment are denoted by the same reference numerals, and descriptionthereof will be omitted.

As illustrated in FIG. 24, the mount mechanism 5000 according to thepresent embodiment has, in order from the side to which the lens mountis attached, an operation portion 5030, a fixed mount portion 5020, themovable mount portion 5010, and the contact holding member 203, centeredon the optical axis 3000. The operation portion 5030 is a ring-shapedoperating unit capable of rotating on a center axis, and is fixed to themovable mount portion 5010 by screws, by arm portions 5040. Note that inthe present modification, the operation portion 5030 and movable mountportion 5010 are fixed at two positions, using two arm portions 5040disposed in an orthogonal direction as to the center axis. According tothis configuration, by the operation portion 5030 being rotationallyoperated, the movable mount portion 5010 also rotates integrally withthe center axis as the center.

Provided on the movable mount portion 5010 are movable mount claws 5011a, 5011 b, and 5011 c, that are each capable of bayonet-coupling withbayonet claws 301 a through 301 c provided to the lens mount. Alsoprovided to the movable mount portion 5010 is a screw portion 5012 thathas been threaded around the center axis, and the screwed state as to alater-described screw portion 5022 of the fixed mount portion 5020changes in accordance with the rotation of the movable mount portion5010 around the center axis.

The fixed mount portion 5020 has a camera mount face 5021 that comesinto contact with the mount face of the lens mount 301, and the screwportion 5022 with which the screw portion 5012 of the above-describedmovable mount portion 5010 is screwed. Unlike the above-describedmovable mount portion 5010, the fixed mount portion 5020 does not rotateon the center axis in accordance with rotation operations of theoperation portion 5030.

Next, the bayonet coupling method of the mount mechanism 5000 accordingto the present modification will be described with reference to FIGS.25A through 26C. Note that the bayonet claws provided to the lens mountare in a state of being capable to engage the movable mount claws 5011 athrough 5011 c of the movable mount portion 5010, in a state of beingpassed through an opening portion of the operation portion 5030 and anopening portion of the fixed mount portion 5020. The state illustratedin FIGS. 25A through 25C is a state where the operation portion 5030 issituated at an unlocked position. In this state, the lens mount face ofthe lens mount and the camera mount face 5021 of the fixed mount portion5020 are in contact, but the claws of each of the lens mount and movablemount portion 5010 do not engage each other, and do not overlap, asviewed from the center axis direction. FIG. 25C is a cross-sectionaldiagram taken along cross-section XXVC-XXVC in FIG. 25B. FIGS. 26Athrough 26C exemplify the mount mechanism 5000 in a state where theoperation portion 5030 has been rotationally operated from this state.

The state illustrated in FIGS. 26A through 26C is a state where theoperation portion 5030 is situated in a locked position. In this state,the claws of each of the lens mount and movable mount portion 5010overlap each other, and thereby are engaged in the center axisdirection. In this state, the screwing state of the screw portion 5022of the fixed mount portion 5020 and the screw portion 5012 of themovable mount portion 5010 changes in accordance with rotationaloperation of the operation portion 5030, and the movable mount portion5010 moves toward the imaging device side in the center axis direction.FIG. 26C is a cross-sectional diagram taken along cross-sectionXXVIC-XXVIC in FIG. 26B. As illustrated in FIGS. 25C and 26C, themovable mount portion 5010 moves away from the fixed mount portion 5020in a center axis direction of the mount depend in accordance with anon-locked state of the mount mechanism 5000 changing in a locked stateof the mount mechanism 5000. According to this configuration, each ofthe movable mount claws 5011 a through 5011 c in a state of beingengaged with the bayonet claws at the lens mount side moves toward theimaging apparatus side.

As described above, the mount mechanism 5000 can move the movable mountportion in the center axis direction as to the fixed mount portion, byrotating the movable mount portion that has claws capable of engaginglens-mount-side claws on the center axis. According to thisconfiguration, the mount mechanism 5000 according to the presentembodiment can reduce occurrence of gaps (looseness) that occurs betweenthe lens mount and camera-side mount in a coupled state.

Although a configuration has been described in the above modificationwhere the mount mechanism 5000 is provided to the imaging apparatusside, this can be applied to a configuration where the mount mechanism5000 is provided to a camera accessory side, such as an interchangeablelens or the like.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2017-108279 filed May 31, 2017, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An imaging apparatus, comprising: a second mountarranged to couple with a first mount provided to an accessory, whereinthe second mount includes a plurality of mount claws that arranged tocouple with a plurality of claws of the first mount by a bayonetcoupling method, a plurality of contact pins that are disposed on thesecond mount following the circumferential direction of the secondmount, and that are arranged for electrical connection, and a holdingmember configured to hold the plurality of contact pins, wherein thesecond mount is arranged to be relatively rotated as to the first mount,between a first state where the accessory claws are each insertedbetween each of the plurality of mount claws, and a second state wherethe plurality of mount claws are each engaged with each of the claws ofthe accessory in a center axis direction of the second mount, whereineach of the plurality of contact pins correspond to respective contactfaces disposed following the circumferential direction of the firstmount at the accessory, and the corresponding plurality of contact pinsand the plurality of contact faces are electrically connected in thesecond state, wherein each of the mount claws extend radially over anangle range in the circumferential direction of the second mount, and afirst mount claw of the plurality of mount claws is included in an anglerange between a line where a first contact pin of the plurality ofcontact pins and the center axis are connected in the radial directionof the second mount, and a line where a first contact face of theplurality of contact faces and the center axis are connected in theradial direction of the second mount, in the circumferential directionin the first state, wherein the first contact pin is a contact pin thatcomes into contact first with the plurality of contact faces, duringrelative rotation between the second mount and the first mount from thefirst state toward the second state, and wherein the first contact faceis arranged to come into contact first with the plurality of contactpins, during relative rotation of the second mount and the first mountfrom the first state toward the second state.
 2. The imaging apparatusaccording to claim 1, wherein the plurality of mount claws are arrangedsuch that each starts engaging with the corresponding claws in a statewhere none of the plurality of contact pins and the plurality of contactfaces are in contact, when relatively rotating the second mount and thefirst mount from the first state toward the second state.
 3. The imagingapparatus according to claim 2, wherein the plurality of mount claws arearranged such that each starts engaging with the plurality of claws atgenerally the same timing.
 4. The imaging apparatus according to claim1, wherein, in the first state, the plurality of contact pins are incontact with none of the plurality of contact faces.
 5. The imagingapparatus according to claim 4, wherein the holding member has a firsttier and a second tier such that the positions where a first sub-set ofthe plurality of contact pins is located differs in the center axisdirection from the positions where a second sub-set that are located onthe second tier which protrudes further toward the accessory side thanthe first tier in the second state.
 6. The imaging apparatus accordingto claim 5, wherein the first contact pin is located at the first tierof the holding member.
 7. The imaging apparatus according to claim 6,wherein the first contact pin is disposed at the closest side in thedirection of mounting the accessory as to the imaging apparatus, at thefirst tier of the holding member.
 8. The imaging apparatus according toclaim 1, wherein the first contact pin is a contact pin arranged toindicate the ground level of one of the plurality of contact pins. 9.The imaging apparatus according to claim 1, wherein the first contactpin is a contact pin arranged to detect whether the accessory is mountedto the imaging apparatus.
 10. The imaging apparatus according to claim1, wherein an angle range in the circumferential direction of the secondmount differs between at least two mount claws of the plurality of mountclaws.
 11. An accessory, comprising: a second mount arranged to couplewith a first mount provided to an imaging apparatus, wherein the secondmount includes a plurality of mount claws arranged to couple with aplurality of claws of the first mount by a bayonet coupling method, aplurality of contact faces that are disposed on the second mountfollowing the circumferential direction of the second mount, and thatare arranged for electrical connection, and a holding member configuredto hold the plurality of contact faces, wherein the second mount isarranged to be relatively rotated as to the first mount, between a firststate where the claws are each inserted between each of the plurality ofmount claws, and a second state where the plurality of mount claws areeach engaged with each of the claws in a center axis direction of thesecond mount, wherein each of the plurality of contact faces correspondto respective contact pins disposed following the circumferentialdirection of the first mount at the imaging apparatus, and thecorresponding plurality of contact faces and the plurality of contactpins are electrically connected in the second state, wherein each of themount claws extend radially over an angle range in the circumferentialdirection of the second mount, and a first mount claw of the pluralityof mount claws is included in an angle range between a line where afirst contact face of the plurality of contact faces and the center axisare connected in the radial direction of the second mount, and a linewhere a first contact pin of the plurality of contact pins and thecenter axis are connected in the radial direction of the second mount,in the circumferential direction in the first state, wherein the firstcontact face is a contact face that comes into contact first with theplurality of contact pins, during relative rotation between the secondmount and the first mount from the first state toward the second state,and wherein the first contact pin is arranged to come into contact firstwith the plurality of contact faces, during relative rotation of thesecond mount and the first mount from the first state toward the secondstate.
 12. The accessory according to claim 11, wherein the plurality ofmount claws are arranged such that each starts engaging with thecorresponding claws in a state where none of the plurality of contactfaces and the plurality of contact pins are in contact, when relativelyrotating the second mount and the first mount from the first statetoward the second state.
 13. The accessory according to claim 12,wherein the plurality of mount claws are arranged such that each startsengaging with the plurality of claws at generally the same timing. 14.The accessory according to claim 11, wherein, in the first state, theplurality of contact faces are in contact with none of the plurality ofcontact pins.
 15. The accessory according to claim 14, wherein theholding member has a first tier and a second tier such that positionswhere a first sub-set of the plurality of contact faces differs in thecenter axis direction from the positions where a second sub-set that arelocated on the first tier protrudes further toward the imaging apparatusside than the second tier in the second state.
 16. The accessoryaccording to claim 15, wherein the first contact face is located at thefirst tier of the holding member.
 17. The accessory according to claim16, wherein the first contact face is disposed at the closest side inthe direction of mounting the accessory as to the imaging apparatus, atthe first tier of the holding member.
 18. The accessory according toclaim 11, wherein the first contact face is a contact face arranged toindicate the ground level of one of the plurality of contact faces. 19.The accessory according to claim 11, wherein the first contact face is acontact face arranged to detect whether the accessory is mounted to theimaging apparatus.
 20. The accessory according to claim 11, wherein anangle range in the circumferential direction of the second mount differsbetween at least two mount claws of the plurality of mount claws.